Here are some interesting things I've learned:
1. Torches can be put on fences! Super cute for the aesthetic!
2. Grass can be put in barns/coops, houses, sheds, the cave, the greenhouse, and some other places I probably forgot of.
3. You're able to change the color of gates by putting an iron, stone, or hardwood fence down and then putting the gate on top of it!
4. You can move chests without emptying everything out! Just select an empty spot in your own inventory and repeatedly interact with the chest until it "hops".
5. Prismatic shards in your junimo hut will make the junimos rainbow colored!
6. If you put a prismatic shard OR a rainbow shell with a piece of clothing in a sewing machine, you can manually pick the color of the clothing instead of dying it.
7. You can put wood or stone signs on a fish pond and it'll display the fish and how many fish you have.
8. You can upgrade other people's tools (like your friend's tools when they're offline) and have multiple sets of tools!
9. You know the little drawers on the side tables? If you place a table on top of the other, you can then take the top one off and rotate it so it doesn't show the little drawer thing and looks like a normal table. A very oddly specific thing, but it's great for decorating.
10. If you desperately need to talk to Robin on Tuesday; wait for her to walk by the desk in the morning and you can build or buy things from her that day.
11. You can destroy bushes on the riverland or forest farm with your axe.
12. WORK BOOTS ARE VERY HARD TO FIND