I usually pick the characters that need to train in order to become better. That is, if I create a character on PS that I've already created in a story or something. So really, the only character I have now actually trains non-stop. Heck if I had the money and time she'd be the top level Axe-fighter XD. But even if I did use that character that was a master, I'd still be training him/her. Of course, I would have a reason to roleplay it as well. That, and I never -EVER- choose a perfect character to use or play as X3 I always write up a flaw(s) for my characters. Whether it be something as simple as... <*comes up with a quick sentence*>
"Although he demonstrated the power that he held in his hand, he quickly dropped the sword and fell to his knees. The strength that he had quickly faded, even when he wasn't finished with his battle." Flaw? Either not fit or doesn't have a lot of stamina :3 Of course, I would have to write more in order to get a better description, but I just wanted to do an example.
Or something as complicated as phobias, genetic disorders, or mental disorders.
Flaws are what make characters seem real ^^ Being perfect at everything just makes them feel fake, or they're a legend, or something that has been exaggerated in order to prove a point. Perfection makes a flawed character X3