How do you decide when to stop synthesising?

So, I picked up The Dark Prince back when it first came out, fell off of it after a bit, but now I'm trying it again. But as I play, I find myself running into the same issue I did before: namely, that I can't stop synthesizing.

The reverse search feature is a great addition, except now that I have a clear list of all the things I 'could' make, I find myself wanting to make them. But I can't just sit around endlessly synthesizing, because every new monster I synthesize in turn is going to open up new synthesis options.

So how do you guys do it? Are there certain 'break points' or 'rules' you set to keep yourself from mindlessly synthesizing the entire library immediately?