It seems to me you know why you are deciding to make it in the first place. What is that reason? Are you saying that most of the stuff you make is just because you want to make it as opposed to making it for a family member or as a gift? If so, why?
I mean, suppose you have decided to make an nightstand ... well, why did you decide to make that? If not to put it next to the bed or give it to someone, then what ... to learn how to make it?
I am like that ... there are lots of things I want to learn how to make, but noone has expressed a need or desire for anything. For example, I really want to learn how to make an entryway table with a curved front and a hidden drawer on the side. But we have no need for one, so I need to figure out what I would do with it when it is done. There is a farmer's market nearby where people can sell stuff. I might take it up there and see if someone would buy it.
I guess what I'm saying is that part of the decision process to make something should be knowing what you will do with it when you are done. If you intend to keep it, then you should probably know where you will keep it. If you don't have anywhere to keep it, then you are eventually going to end up with a cluttered space, which is not healthy.