From a short experience as a contract-less freelancer: People will try to take advantage of you. Once the product is finished (or close to), they will try to s

From a short experience as a contract-less freelancer: People will try to take advantage of you. Once the product is finished (or close to), they will try to scrap what they can, host it on their own and stop paying you. You will need to figure a way to stop this from happening For me it was installing WordPress with themes that would ping my server. Anyone with PHP knowledge would be able to figure it out in a few hours, but it stopped most "non-technical" users from trying anything weird.