Hmmmm....I have so much to say here about my own experience! I feel like I've always been trying to feel fab and only sometimes achieving my goals. In the past few months, so very recently!, I think I'm finally starting to get the hang of it.
First, for me, I have to calm the F down, IFYKWIM. Like, relax. I realized that a large part of my confusion here is because I ACTUALLY AM NOT SURE WHAT I LIKE. I'm not (yet) someone who can walk in to my closet and be inspired by what I see. What do I feel like wearing today? Is not a question I can always answer. I'm working on slowing down and really trying to feel myself and what I WANT and LIKE. Not on others (although being inspired by others is good) but ON ME.
I haven't had time, but I think playing around in your closet and trying different things and really getting a sense of what feels right for your personal style is the way to go. I also have a few items that, like, look fine in theory but I felt like they just weren't for me when I wore them (even though they fit and looked perfectly fine). When that happens they go straight to the donate pile. If I have pieces that I subconsciously react to in a negative way, I donate them.
Shopping is still a bit of a mess, because I don't know if I'll love an piece till I've gotten to know it and introduced it into the "closet ecosystem". But I think my intuition is getting better as I edit more authentically.
TL;DR
Focus on what gives you that thrill; style is a sensory experience. Slow down and enjoy the process; don't dwell on closet or dressing mistakes. Focus on the successes.