3rd time is the charm?

I've knit a plain black top-down raglan body twice already and each time, I had to rip and start again. I'm almost finished a third attempt now and I hope with all my heart that it is going to be close to fitting my actual body and not some other body who is twice my size. I don't know what is happening - I'm measuring and calculating but nothing is ending up the way it should. I suspect it's an issue of ease. I'm still not sure how to deal with calculating ease into my patterns - do I need two inches? No inches? Negative? I don't quite get it. Does anyone out there have any suggestions of how to deal with the ease problem? Cause trial and error just isn't cutting it for me. Anyway, that should explain why I have nothing to show you - I've been knitting black stockinette for two weeks straight.

Maybe I'll take a little Demi break to calm my nerves.