technique and practise count for everything in palpation
make sure you use your finger tips (where the pulps are) - and NOT the side of the fingers as many 'senior' examiners will show (as in senior, i mean outdated and illogical). the fine touch and pressure sensitive receptors are in greatest density at the tips of your fingers, not on the sides.
practise on all sorts of objects, and get used to various shapes. if you're really really struggling to feel - you may have a neurological condition. otherwise, you could always make friends with the people down in the mortuary and say you want to palpate some organs. there you can press as hard as you like, and spend as long as you want. once you get a feel for how things should feel under your hands, you can start getting softer and softer, and then try it on alive people.
and finally, the most important rule of learning clinical medicine - whenever you see an interesting patient with your team, or on rounds.... ALWAYS go back and examine them fully - and dont just go back on your own. Take a friend. This is the most important advice -