befriend Caroline (Pierre, the store owner’s wife) ASAP, when she’s at 2 hearts enter her sunroom through the back door in their kitchen. The next day you’ll get a recipe in the mail for Tea Saplings.
I didn’t get this tip when I first tried it because tea only grows the last week of every season and doesn’t sell for that much. But you don’t plant them, chuck them straight into the shipping bin (or sell to Pierre if you need the $ that day.)
They sell for 500g each - use this tip sparingly if you don’t want to break the game. I typically use it for emergency cash like “Oh no, I forgot the egg festival was tomorrow and have no money” or “I need to upgrade my watering can while it’s raining but I forgot and bought a backpack upgrade instead”
Other tips:
get a coop and some chickens as soon as is feasible (and after building a silo)
selling mayonnaise is a lot of money in early game
farm animals are a consistent source of Farming Exp (with crops you get Exp when harvesting, but with chickens you get Exp daily from petting them)
parsnips don’t sell for much, they might be better used to befriend an NPC
spoiler
Pam because she sends items in the mail that are really useful
if you randomly get mail from an NPC you’ve befriended (e.g., not after a quest) you can restart the day to get the item you want (out of the small selection of items that each NPC can send you- a few examples below hidden in spoiler tag - some of these are useful for completing the Community Center)
You can lay down in your bed without sleeping to slowly regain energy
Plant tree seeds in the dirt patch areas of the forest to have a larger supply of wood without sacrificing farm space
Chests in strategic locations (e.g. in the mines, by the bus stop, etc.) with area specific items (e.g. food for mining, gifts for villagers, etc.) to save time traveling back to the farm
Invest as much as you can in seeds. Cauliflower, melon, and pumpkin will have the best return on investment your first year, so plant as many of those after you have minimum required of the other crops. Plant crops with multiple harvests per season (blueberries, hops, etc.) ASAP, ideally day 1. Sell crops directly to Pierre on harvest day so you can buy seeds to replant the same day
Don't waste an inventory space on staircases. Bring 99+ stone and craft if/as needed
Sashimi is a low effort/low opportunity cost food. I recommend using crab pots on the farm to supply the low effort fish. The recipe is from Linus, if I recall correctly.