Sometimes I'll just buy a regular face powder a few shades darker and use that as a bronzer. Or if I'm running out and i need a sub, I'll take whatevers left of my bronzer with me and look for a powder in the drugstore that sort of matches it.
It helps becuase a lot of bronzers I find are orange or yellow and I'm yellow-olive so I have to do this a lot lol.
Just make sure to apply lightly repeatedly so you don't go overboard