I always aim to keep my collection as small as possible, so I'm getting rid of a doll in favor of a new release now and then.
I don't know if it helps in your particular situation, but here is my usual procedure:
First off, I always set a limit. For example: "I'm only allowed to have two dolls of each character" or "I'm only allowed to have 40 dolls total".
Then I try to determine the dolls that can stay by asking myself:
- Which character do I like least?
- Which face mold do I like least?
- Which color combo do I like least?
- What outfit looks best to me?
This is usually a good method to narrow a collection down.
I hope you're not too emotionally attached to the dolls of course. Because otherwise it can get a little hard to say goodbye.