I too wear clothes until I need to buy new ones.
When I go to concerts and see bands I like, I like to support them by buying some merch, which includes at least a T-Shirt. The ticket sales and merch sales support a band moreso than the raw sales of the music itself, so I make it a point to support groups I like.
For example, I'll be seeing my favorite band, Iron Maiden, in concert yet again coming September 19th. This will be my fourth time seeing them, with Trivium opening for them, so I at least want to get a Trivium T-Shirt and yet another Iron Maiden T-Shirt.
I also try to buy shirts from local ma and pa shops that I like. I like supporting local businesses. Even though I've quit nicotine altogether, I still am good friends with the owners of a local tobacco and vape shop, so I own a T-Shirt or two of theirs. And a local whisk(e)y bar I've bought a personalized Glencairn with my name on it.
Basically, I just buy new clothes when I need them, and if I like you, like your business or what you do and you have merch, I'll probably buy at least a T-Shirt.
Outside of that, I dress for comfort. Jeans, sneakers, T-shirt. No need to overcomplicate it.