if you want the best results, get a plastic bag and tear a corner off... force your finger into the plastic so that it stretches the bag around your finger so as to be skin tight...
now put a pea sized amount of thermal paste onto the cpu and rub it in to the cpu so as to fill as many microscopic holes as possible.
try to make it thicker in the center. i also rub/tint a tiny layer onto the cpu cooler and fill any big gaps completely... builders secret... after 10 years ive decided to share...
usually 1-5c differance to just placing the pea sized dot 80% of the time...
just try to avoid putting too much on...