MORE gold THAN level

Stay at a low level till you build mills, plant trees/shrubs, or place harvesters.
Otherwise the post will be just full of orders you can't response.
 

How To Earn gold : INVESTMENT

STEP 1 : LEVEL 6〜
Unlock Wesley's Exports
and sell fish like crazy.
You'd better have 2 Turtles & 2 Island Workshops.
Fish is very cost effective.>>PROFIT @MARKET
You can put up to 10 fishes in one slot in Wesley's,
but it sells faster if you put just a few at a time.
Don't sell pearls!
STEP 2 : LEVEL 10〜
Unlock four docks as soon as possible.
Merchant Ships give you more gold than levels.
Not all merchants offer you good deals.
But I'd think it's worse to keep those bad-dealers long at your port. Go trade with them, and send them away so a new good-dealer would come to you.
Only,
Don't sell pearls!
Sell plutinum & ruby.
You only need plutinum and ruby for decor items.
Just sell them away at this stage, you can decorate your island when you have enough room in your storage and lands.
>>STONES & DYES
STEP 3 : LEVEL 12〜
Unlock World Market,
stop growning pineapples,
and grow other crops on your fields.
The market is flooded with pineapples.
I believe it's not just current trend. Pineapples will always be amply sold cheap in the market, for, as you go on the game and unlock Chameleon Cove, Mai the owner of the island offers you bunches of pineapples fairly cheap.
STEP 4 : LEVEL 15〜
Unlock Bazaar and buy recipes.
>>RECIPES
STEP 5 : LEVEL 17〜
Unlock Map Table, and then islands ASAP.
When you unlock islands:
Dreadbird's Fort You can rely on Dreadbird for supply of iron ore, and dedicate your mole to silver/gold which takes looooong time.
Style Isle You can make fortune by reselling outfits.
To unlock the islands above, you'll need map_keyMap Key
and the ship merchant who trades it requires
sunfishSunfish and rainbow_fruitRainbow Fruit.
So, first you've got to unlock Angler Island & Chameleon Cove.
Add outfit-resellers to your friends.
Players who already have unlocked islands most likely sell goods required by map merchant, or Map Key itself (and occasionally pearls.)
You can always see your friend's displays in the market.
If you find at the market a player who sells heaps of outfits
or golden_fleeceGolden Fleece
add him/her as your friend right away.
>>How To Add Friends
STEP 6 : LEVEL 20〜
The mills get expensive now.
Tighten your purse‐strings!
If you got extra gold to spend, unlock the cave up north on the island.
A new character clara joins.
Just keep in mind that you need to build relationship with her for recipes,and pearls need slots in the storage.
You need powder_kegPowder Keg to unlock the cave.
Leave Seal Divers till you get much gold to spare.
The seal will dive only once a week.
And you've got to get online every couple of hours to get items.
STEP 7 : LEVEL 29〜
The mills get WAY expensive.
Discard orders which gives you more level points than golds.
order
 

Keep Crops ON THE FIELDS

Never fill your Windmill Storage.
Just harvest crops as you need, replant the half and use the half.
Maybe you need about 10 stocks each of vanilla, sugar cane, and tree/shrub crops which takes long to grow.
 

Store LongTerm Products

Merchant Ships don't wait for you. Always keep stocks of goods which take more than an hour to make.
The problem is: Treehouse Storage takes long time to grow, too.
Give anything to merchants who trade green Upgrade Resources, (blue is for crops, green is for mill products) and look around the island for treasure chests & clams.
>>Upgrade Resources
You don't need plutinum, ruby, and dyes at early stage of the game. Don't store them, just sell them away at Wesley's.
>>STONES & DYES
 

What to Spend Gems On?

Get slots in Wesley's
Sell more products, get more golds.
It helps when you got stuck with your storage full: you can put surplus up for sale.
Get slots in mills.
You can give more order to the mill at one time, and have less need to get online.
Island Outfitters will go extinct when you unlock Style Isle.Don't buy slots for Island Outfitters
 

Enjoy Decorate Your Islands.

deco_1
Fields can look pretty.
deco_2
Otters float hands in hands.
deco_3
You can move Map Table.