Practice, practice, practice. Get somebody to show you the ropes until you can roll a smokeable blunt on your own. Once you get to this point, refine your technique (just practice rolling up with blunt guts if you're worried about wasting weed). Try different ways of getting your blunt tighter, learn what consistency of ground up weed you roll best with, discover if it's easier for you to roll with or without using a flat surface, find your favorite brand of cigars for rolling purposes...
I've got tremors like a motherfucker that run through my hands, to the point that I thought I had Parkinson's when I first heard about the disease (thanks, McFly), but I can roll with the best of 'em-- it just takes me a little more time. I almost exclusively roll Dutchmasters and tend to table roll and pearl (remove outer leaf, set to side, table roll Dutch like normal, fit crutch/filter/roach into the end I'll be inhaling from, table roll the outer leaf back onto Dutch). I take pride in my Dutch's, and definitely enjoy the compliments I receive every now and again because of them.
If it's joints that you have trouble with, though, then I don't have much to offer. I started out rolling with paper, and just transferred those skills over to rolling blunts... It might be in your best interested to get a rolling "machine" and observe the hell out of how it rolls your joints, and then try to reconstruct the process using your hands.