It takes a"feel" for the bolt being tightened, and a little common sense. When you are tightening the bolt, nut, whatever and it starts "feeling" DIFFERENT?....Thats either the threads stripping, or the bolt shearing. ALL'S that is NEEDED, is when you feel the fastener seat?.........I would think, an 1/8 to 1/4 turn would be sufficient , in most cases.
IMHO.......ESPECIALLY, on those smaller threads. If you're worried about the vibration backing them off?........A little lock-tite does good. If you think that you can tighten these smaller threads ONE TIME and NEVER have to check 'em again?....In more cases than not, you're going to twist off or strip it!!
Hope this helps.