I know I'm gonna hear the usual crybaby comments but I don't care. I'm gonna vent here because you seem to be frustrated too.
I get the lip out because certain short putts require you to hit it quite firmly downhill. If you don't get the line just right, it lips out real easy. I been doing that too much and it pisses me off.
If you don't get the speed of a putt just right, I find that lip outs occur more if I tend to hit it a little too firm. But if you don't hit it firmly enough, you aint gonna make the putt so it's kind of a catch 22 there.
I have been so gawd damn frustrated latley with this putting I'm thinking of taking some time off. It's like the dame thing don't want me to have a killer round. 40 ft putts stopping 2 inchs from the hole. It's getting to where, why in the hell smack my own toe with a hammer anymore, for fun? meh
But I feel you. The answer is to get the speed and of course the line correctly.