You should definitely wait until the clones are thriving before you start snipping the tops off of them, but yes... you can top your plants several times to make them fill out instead of growing vertically so much. You can also train them (type "LST" in the search bar for more on that). I wouldn't start training or do any cutting until there's noticeable new growth, though, so that you know the root system is firmly established and thriving.