Instructions
Buy a shovel from Tom Nook for 500 bells. Search the town for star-shaped markings on the ground. Use the shovel to dig in those areas. Bring any fossils you find to Blathers at the museum for identification. Sell the fossils at Tom Nook's shop. Tom pays between 1,000 and 6,000 bells for each fossil.
Buy a fishing pole from Tom Nook for 500 bells. Equip the pole, look for shadows in bodies of water and then cast near them. Sell the fish you catch to Tom, who pays between 100 and 15,000 bells for a single fish.
Catch insects with a butterfly net, which you can buy from Tom for 500 bells. Sell the bugs to Tom, who pays between 80 and 8,000 bells for each one.
Collect fruit from the trees in town. Press "A" to shake a tree and then press the "Z" button to pick up a fruit. Tom Nook pays 100 bells for apples, oranges, cherries, peaches and pears and 500 bells for coconuts. Plant additional trees to increase your fruit yield.
Pick up seashells that wash up on the beach. Tom pays between 30 and 1,200 bells for shells, depending on the type.