Referring to groups of people

Question

If I was to refer to people who like fish, I'd say something like 「魚が好きな人」, but if I was to refer to people who do something, how would I go about saying that? Would the format be similar, or would it be completely different. I know in Japanese, to like is treated as an adjective, where as, someone doing something would be a verb, so if I was to refer to people who wear pants, would I say it as something like this 「ズボンを履いている人」? I'm not sure if I'd use the TE form of the verb, or if I'd have to use a different form, nor am I sure if I need to use いる or ある. I went with いる, as I'm referring to a live, animate person, but I'm not even sure if I'm even remotely close to saying it properly. Is there some other particle I'd need to use, or a different sentence structure? Or would referring to a group of people based on something they do, such as people who wear something, people who exercise, or certain actions be unnatural in Japanese?