You can synthesize the ultimate Gelato from Sour Cream and Condensed milk.

$500 spent at Harbor Freight and a year of watching Car videos in your Youtube Time can make you a mechanic for 90% of the problems cars have.

There is no shame in buying a finished product to break down for components if it's faster/cheaper/better than buying a specialty part. Don't forget, older electronics have a Lot of components in there you can yank out wholesale.

There is no shame in re purposing technology. Off-road LED lightbars make excellent landscape lighting.

3D printing is Great but we've had Jbweld and Dremels for years. Don't let your lack of imagination stop you, there's plenty of ways to make a plastic repair part that doesn't require PLA. Literally thousands of polymerizing chemicals out there to fill every hole.

HDPE greenhouse plastic, available in the back of any Home Depot is a miracle material nobody thinks about. Especially if you're Homeless or otherwise trying to be a Human out in Nature, HDPE film is like a Magic barrier that lets light thru but blocks everything else.

Large panels of high strength and stiffness can be made with pink insulating foam sandwiched between pieces of Plywood or Masonite/MDF. Cheap panels can be made up with spray adhesive and thin plywood, structural panels can be made of marine grade plywood and flame-retardant foam.
The structural rigidity and acoustic properties of this composite material are astounding. I rode 30 miles on a vehicle framed with the stuff. (It rotted eventually, oops)

Parachute cord can be butt-welded to 50% of it's initial strength with a candle or small propane torch. This means rings and hoops of the material can be made easily, and knot ends finished smoothly.

DIY vape juice flavorings are the same stuff that goes into literally everything else. Soaps, drinks, scents, air fresheners, everything. I bought a flavor called Summer Clouds and it tastes like a glade plug-in. If you want that Very Specific fursona spray or soda combo, these are the way to go.

A couple pieces of basic paintball equipment and a trip to autozone for a pop-in valve stem and a tire inflation chuck will allow you to carbonate your own soda at home without any of that sodastream nonsense. Add in an old pressure cooker, and you can now carbonate Fruit, Jello, basically anything with Water in it.