For those fingertip cracks, I just put a very small drop in the crack, then wick up the excess with the tip of a tissue. Once the glue is dry, the crack is immobilized and won't crack any further. Usually the crack will heal right up.
Treating cuts is pretty much the same thing. The worst cut I ever glued together was when I cut my finger nearly to the bone with a filleting knife. I probably should have gone to the emergency room. but glue did the trick.