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First thing is clear your beaches of seashells daily and sell them. Might not make a lot, but it adds up over time. It also helps contribute to your "Go Ahead. Be Shellfish" objective. (You need to sell 1,000 shells total to complete it fully)
Sell your native fruit on islands that have a different native fruit!!! You'll get more bells for selling non-native fruit. Also make sure you trade fruit so that you have fruit thats not native to your own island to sell at your own shop!
Dig up all your daily fossils and have them assessed by Blathers. Once you collect ALL fossils and it gets to the point where you can't donate any new ones, you'll make a bunch of money selling your duplicate fossils.
TURNIPS. Daisy-Mae comes every Sunday morning from 5am-noon and the goal is to buy low so if she's selling turnips for less than 100 thats great, if its 100-110 thats still not bad however you'll want to sell them at higher prices.
Continuing onto the topic of turnips, Nooks Cranny will buy turnips Monday-Saturday. Theres one price in the morning & another in the evening. Try to sell turnips only when they are buying for over 150 bells each. Preferably higher though.
You can find out other peoples turnip prices by using discord, reddit, facebook, whatever animal crossing groups you are apart of.. as well as Turnip Exchange but beware of scammers! Turnips can be a fantastic way to make money in this game.
Some things to be wary of with turnips though is they will rot if you do not sell them by Saturday night. They will also rot if you time travel backwards for even a minute. That being said, you can time travel forward with turnips safely (as long as you sell them by Saturday!)
Now rotten turnips do come in handy if you are trying to catch ants or a fly, but the goal is obviously to sell them for a profit. Hope this thread comes in handy and if anybody has contributions to add, feel free!
