My biggest tip for future designers is to not be afraid to experiment.
Also, Go large. Stop making what ever signature your making and open a new file at least 4"x6".
One of my biggest regrets in digital artwork was not going bigger when i had the chance, Climb up to that high dive and jump.
Theres nothing wrong with testing the temperatures of the water with your toes first. ( signatures )
Just don't waste your time playing in the shallow end, work up the courage to do a print. Then a T shirt, then a website.. Then Canvas, then start rendering you work High Definition with projectors.
This industry is about progress and the future, Learn to embrace technology and work with it.