This is a guide to making insane profits in Harvest Moon DS right from the start, and accomplishing a great deal in only 3 seasons. Note that only money-related tasks are listed; you're free to spend any extra time you find yourself with and any extra funds you find you have however you'd like.
Please take note that this is not a strategy for the impatient. If you want to get an insane head start, you really have to work at it.
This guide can be used with both Boy and Girl versions of the game. You will need both save slots available. See the Money Making Guide for info on how to hunt down cursed items in the third mine effectively, as well as other handy tricks used in this guide.
Version 1.10 (12 April 2008)
* Changed the guide a bit to accomodate for the Cute version
* Fixed an error concerning getting the Fishing Rod
Version 1.00 (24 March 2008)
* Initial version
Decline the Mayor's help. Immediately head for the excavation site, and using the save/load trick, mine up 50 pieces of jewelery. Ship 1 piece of jewelery out via the shipping bin before 4PM, and as soon as it's 5PM, call the Supermarket and buy the Medium Rucksack. Visit the mines afterwards, when nobody is present there, to unlock mine #1. Do not enter yet; just go to bed instead.
Target Funds: 500G
Visit the excavation site again, and dig up another 75 jewelery (or however much you can manage before your character shakes his/her head). Wait outside the inn until 10AM, then enter and sell your jewelery to Van for no less than 3000G each. You should have around 372,500G to work with. Buy 99 Turbojolt XLs and 99 Bodigizer XLs, and use one of each. This will leave you at 75,500G or so.
Next, visit the mine and dig up another 75 pieces, sell to Van again for 3000G+ each, and buy a Goddess Hat; equip it. Return to the excavation site and clear mine #1, then resume mining up the excavation site for more jewelery until you can afford to hire Gotz to build a stone Bird Shed (all upgrades should be done in stone); do so and pay for materials.
Level up all of your tools to 400% (you'll need to repeatedly ingest Turbojolt XLs, but the Goddess Hat will help), and hire Blacksmith Saibara to upgrade the Watering Can to Mystrile (you can get some in the first mine if you didn't already). After that, build up funds digging up jewelery to sell to Van (target is a million G), restock on Bodigizer XLs and Turbojolt XLs, heal up and wait.
Visit the excavation site once Carter and Flora have left, and then unlock the second mine; you'll clear it later.
Target Funds: at least 1,000,000G
Return to the excavation site and get a Cursed Kappa Hat; uncurse it for 100,000G. Gather and uncurse all of the Cursed Tools too; you can in fact find them before you have Mystrile tools, and you'll need them for what's coming. Make sure you buy something from the Supermarket today (I suggest 36 bags of Turnips to plant in the Super Field come the 7th; keep it replanted with 36 bags regularly until you have the Seed Maker).
Target Funds: around 300,000G
Spring 5th, 6th, and 7th
Keep your chain of upgrades going. When you get back your watering can, upgrade another tool (any will do; now that you have the Blessed tools, it's entirely up to you). Have Gotz start on an Animal Shed next. Keep buying cheap things from the Supermarket, one a day each day they're open. Visit Nina and Galen (talk to each once, then re-enter their house with no tool equipped) just after noon and get the Fishing Rod on the 7th. Then get all tools up to 400%, and reach the bottom of the second mine. You don't have to focus on collecting anything this time; just get to floor 255 and get the Legendary Sword (if you can, which you should be able to). Unseal the Super Field behind the waterfall, plant it with your Turnips you bought earlier, unseal the third mine, then head home.
Target Funds: Unimportant as long as you can afford all the upgrades during these 3 days
Depending on your version of the game, either gather a bunch of Cursed Kappa Earrings, or gather a bunch of Alexandrite and Pink Diamonds. Either way, sell them to Van for a boost in funds; you'll want at least 3 million to work with for the coming weeks. Don't forget to buy from the supermarket.
Go and get a Cursed version of the Time Ring, Goddess Hat, and Friendship Broach; uncurse them and keep them handy at all times. From now on, whenever you travel, keep the Time Ring equipped. Also, this is a good day to unlock the casino Harvest Sprites, particularly Roller (since this is the first day you can unlock him).
Force-buy enough Medals to afford the Teleport Stone, and get it. Keep upgrades going as needed. From now on, wear the blessed Friendship Broach to bed each night.
Target Funds: About 3,000,000G
Rest of Spring
Most of what remains is keeping upgrade chains going. Continue to buy items from the Supermarket (make sure you get the large rucksack as soon as it's available) until you unlock TV Shopping, and once you do, immediately start buying TV Shopping items. Once Gotz is available to, have him build a Maker Shed, House Upgrade #1, House Upgrade #2, Basement #1, Basement #2, and Basement #3.
Each time Gotz completes a basement, be sure he gives you a Spring Sun for the first, Summer Sun for the second, and Fall Sun for the third; you can control this by saving before you leave your house when he's finished a basement, and reloading if you don't get the Sun you want upon leaving your house.
Once the Maker Shed is done, stop upgrading tools long enough to buy a Seed Maker and Cannery Maker (in that order), then resume upgrading. Keep upgrading your tools to Mystrile, and once you have all 6 at max, make your tools into Mythic ones with Mythic Stones from the 2nd mine. Once all tools are maxed, you can buy the remaining Makers in any order.
With the Seed Maker, start converting your 16 highest-leveled Turnips to seeds after each harvest from the Super Field, planting 5 of them in the top-left plot, and the remaining 11 as single bags on the remaining plots. Keep this up, but replant no later than Spring 28th.
As soon as the first basement is done, buy 5 of each seed type save Turnips, make 6 3x3 plots, and plant up the first basement with spring crops. Once you get the Seed Maker, add either Toy Flowers or Moondrop Flowers as well (not both; we want a free plot for Turnips at the end of the season). Similarly, plant the second basement with summer crops (initially you can only plant Pineapples), and the third with fall crops (initially only Green Peppers available). Level the crops as they mature.
You may as well buy a chicken, 3 cows, and 1 sheep now too. Breed more birds and buy more livestock as needed when you upgrade your animal capacity. Be sure to use the Touch Glove to care for your animals, so you can make them win festivals and get leveled produce from them one day.
Any time funds are running short (or will be before the next day ending in 3 or 8), mine up some more Kappa Earrings to bless or Alexandrite and Pink Diamonds, and sell them to Van. Overall, you'll need about 6,000,000G to finish all of these upgrades, but it's far less tedious to get it done in chunks..
As TV Shopping purchases progress, you'll get the Refridgerator and Cabinet. Store foraged goods (which you should be gathering as soon as you can spare the time to do so) inside them.
On Spring 30th, buy up 5 of each summer crop and plant up the second basement with (again) 6 3x3 plots, 1 plot per seed type.
From now on, you will need to keep the cycle of crop leveling going in your basements for all seasons of crops. The three seasonal Super Field crops should be planted in these baseements during the off seasons, and transferred to the Super Field as soon as their season comes.
The first day, gather as many Pink Cat flowers as you can, and convert them all to seeds. Plant up the Super Field with the seeds. You'll want to keep the same cycle as you had going for Turnips in there for Pink Cat Flowers. The last day you can replant is Summer 25th.
Keep the upgrades coming: Pond (get a duck as soon as you have the Pond), Silo, Wooden Lumber Shed, Stone Lumber Shed, Mushroom Shed, 4 more Bird Sheds, and (eventually) 3 more Animal Sheds. Get 20 total birds to unlock a Sprite, then sell off 4 birds and demolish a Bird Shed, and purchase one last Animal Shed (get 10 overall cows/sheep for yet another Sprite). Any building upgrades after that are at your discretion.
On Summer 30th, buy up 5 of each fall seed type (except Yams; get 60 of those seeds), and plant up the bottom basement with 6 3x3 plots, 1 plot per crop type. Plant up the Super Field with all 60 bags of Yam seeds (5 per plot).
For the first 3 harvests of Yams, you'll want to convert the 60 highest-level ones to seeds and replant the field. Once you hit level 5, re-form the field as so (lighter squares are untilled):
Then plant your 60 seeds, but afterwards, only replant the top-left plot regularly. Leave the other 11 plots for daily harvests. This will net you a lot more profit. The last day for replanting is Fall 26th. Be sure to return the Super Field to its normal all-plowed state by Winter 30th, for the Turnip batches of Spring. You'll want to revert it to the above pattern on the 30th of Summer from now on, as well.
By the end of Fall, you should have every upgrade you can get at this point in place.
Rest of Game
Just keep the crop leveling going, transferring Turnips, Pink Cat Flowers, and Yams to the Super Field as appropriate on the 30th of the season before their growing season starts. You can afford anything and everything in the game outside of Gold Lumber buildings and the island by the end of year 1 using this plan.
You should be able to afford the Island by Fall of Year 3.
Upgrade Chain Overview
Tool Upgrade Chain
Watering Can (Mystrile) -> All 6 Cursed Tools -> All 6 Blessed Tools -> Remaining 5 Tools (Mystrile) -> Watering Can (Mythic) -> Sickle (Mythic) -> Remaining 4 Tools (Mythic) -> Remaining 4 Makers
Once the Maker Shed is done, interrupt with: Seed Maker -> Cannery Maker
Building Upgrade Chain
Bird Shed -> Animal Shed -> Maker Shed -> Pond -> Silo -> Wooden Lumber Shed -> Stone Lumber Shed -> Mushroom Shed -> 4 Bird Sheds (demolish 1 after you have 20 birds) -> 3 Animal Sheds (build 3rd after demolishing a Bird Shed) -> House Extras (Bathroom, Toilet) -> Golden Lumber Shed -> Vacation Villa (once you have the Island)
As soon as you get the Table from TV Shopping, interrupt with: House Upgrade #1 -> House Upgrade #2 -> Basement #1 -> Basement #2 -> Basement #3