You might thing that the best penmanship would involve excellent finger control over the pen, but your fingers actually don't help you write better — they can make your handwriting worse. Dyas A. Lawson, creator of pen, paper and writing site PaperPenalia, explains the difference between writing with your fingers and using your shoulders, and why using your shoulders is better.
People who inevitably have trouble with handwriting and calligraphy write with their fingers. They "draw" the letters. A finger-writer puts the full weight of his/her hand on the paper, his fingers form the letters, and he picks his hand up repeatedly to move it across the paper as he writes.
People for whom writing comes more easily may rest their hands fairly heavily on the paper, but their forearms and shoulders move as they write. Their writing has a cadence that shows they're using at least some of the right muscle groups. They don't draw the letters with their fingers; the fingers serve more as guides.
There's more to great handwriting than just taking the strain off your fingers, but it's a good start. For more ways to improve your handwriting, hit up the full post over at PaperPenalia.