I inject all over my belly, but only the fatty bit. I find that whether or not an area hurts is fairly random, and just poke my self gently a few times til I find a spot that doesn’t instantly scream at me.. Usually leads to completely painless injections – even with lantus! And in the mornings (when I’m largely naked anyway) I take advantage of my sizeable flabby thighs and get some 90% painless injections in with very little thought 