I started with a trek 4100, i used to compete XC then i moved to trials and it was to hard to make good moves with that frame and i learned very slow so i didn't like it to much
Watch some pro videos, and try new stuff, try to avoid riding the same place too many times, something that sometimes my friends and i do is to create short zones, that will push u to become a better rider
Why don't u try a short Zoo or may be a monty, i think that monty goes better for some natural riding and it has accessible prices, by the other hand Zoo rocks in street so it's up to u men.