Check that, if they're on the sides then it's either a pinch flat or damaged sidewalls
if they're on the outside of the tube, it's something you're running over like glass or thorns, maybe even a hole in the tire somewhere
if they're on the bottom, it's a spoke poking through a nipple, a nipple itself, or a sharp spot on your rim. check and make sure nothing's poking through there and double check if your rim strip is still good and covering everything. If you don't have a rim strip, get one
Also make sure you're installing the tube properly, crooked valve caps will break and cause flats. pinching the tube during installation will cause flats.