Many years ago when Dr. Phil (yes, that Dr. Phil) was a flash in the pan, I remember watching one of his shows about relationship psychology. In it he simply stated that you make a statement - then anything that follows the word BUT is immediately a way to justify false behavior and invalidates anything said before it.
This always resonated with me and I have used it throughout my years to make myself realize when I'm using false validation to justify what could potentially be a bad choice. It's simple but effective.
Recently on asktrp there have been a rash of "this girl did x BUT" posts. For example: "This girl told me we can't have sex BUT she's a 9 and really cool so should I keep trying". No. Next. Simple answer but many here don't seem to understand it.
This applies to many areas in life. "I want a better job BUT the one I'm in now pays well and gives me benefits. Should I change?" No. Because you don't really want to badly enough, if you did you wouldn't ask the question. "My relationship has all sorts of red flags BUT she's never been shady before, should I trust her?". No. Because you know what she's doing and need to get the hell out. "I set up a date with this girl and she flaked BUT she said she's free next week. Should I give her another chance?" No. If she wanted to see you she wouldn't have flaked.
The next time you make a statement and have to put a BUT with it , think about the original statement and ask yourself if you're really trying to just talk yourself out of a decision or a question that you really know the answer to. Applying this in many areas of your life not only helps you make firm decisions without constantly second guessing yourself but it also allows you to really evaluate what is going on with relationships and even situations you might need a decision about.