This is a great local option. Accordant with their policy, they will accept all clean clothing. Just make sure it's not too worn out.
Old t-shirts have been washed so many times that they are lint-free, and make perfect rags. Cut them up!
They will accept any underwear or socks you can spare and get them to people who desperately need them.
Take an old t-shirt and tie it into a series of knots. Your dog will love it!
Wear them on a vacation, and throw them away to free up luggage space for your return trip.