Boxing is a dynamic sport mate, don't limit yourself to 5 combinations or you are going to become predictable. Personally the only combinations I have are more like rules. Ie if my back hits the ropes I hook and turn the guy, I go for a body rip I immediately throw an overhand right. If your whole offence is based on, jab move in, right cross, etc. etc. people will eventually figure you out. Just try to master each punch, this will allow you to fill any opening you see with the correct punch, rather than a predetermined combination. This is also why experience is so important for boxing.