There is a trans support org in my city that takes clothes donations.

I sometimes straight up ask someone who is homeless and looks like my size if they want whichever particular item, especially if it is comfortable or will keep them warm.

Takes a bit longer but I'm sure they appreciate it more.

My go to lately has been domestic violence shelters.

My local food pantry takes pretty much anything a person could find useful (backpacks, clothes, shoes, etc). Try seeing if there's any local outreach/resource organizations in your area.

Find your nearest trans friend and ask if they know anyone who wants clothes