Changes

When I was in school I learned one really important thing about designing.  It was knowing when to stop the changes.  I like to refer to this point in the design as when you "pick it and stick it".  Unfortunately I'm having a really hard time applying my interior design rule to my crochet design. Every time I'm make a test hat I change the pattern.  The changes aren't big, they are mostly about number of stitches and what rows they go on but they are driving me crazy.  Will I ever hay my hat pattern ready?