EDIT: I added a few things.. can anyone tell I have ADHD yet?

When keeping a plant alive, you need to look up how it likes to be in the wild, and try to EMULATE that best you can. Monstera deliciosa has root rot? Well in the wild their roots are very compacted, maybe that gallon sized pot needs to be downsized. They also grow on trees, give it some support, etc

Cast iron cookware: when seasoning the item you need to apply the thinnest layer of oil possible. It should look almost like you’re trying to wipe the oil away or clean it.

PC building: your local electronics recycler is an amazing place to get simple fundamental equipment. You won’t find a 5090 in the bin, but you’ll find cheap ram, any cable you need is 1$, hell, my NAS is a 22tb (after redundancy) raid array where I paid 7$ for each 2tb drive. Sure, it’s slower and clicks like hell sometimes, but it’s in a closet, and I can lose a few drives before I lose my data.

Car/motorcycle repairs: your local chain auto shop probably loans/rents specialty tools. (This is pretty well known but still) need a tool to compress your brake cylinders when changing pads? It’ll cost 10$ rather than like 80$.

Gardening: mulch. In my area the sun is an absolute killer in the day while I’m working, so laying mulch over the soil keeps it from drying as fast

Cooking: following recipes isn’t that hard for most things, the way you know that you’ve really leveled up is when you start to realize how certain flavors and textures interact, and come up with something new or, more often, start modifying and improving recipes

Terrariums: the most crucial aspect is the amount of water. It will easily make or break (or kill) your plants and design. A good drainage layer, followed by chunkyish soil, and a layer of peat moss is the way to go most times. Also, BUGS. springtails and isopods are a learning curve but are an insanely helpful group of fellas.