I think I've been drawing for about 15 years~ Ultimately, the best pointer and advice I can give to you is practice alot and stay determined! Of course, have fun while you're at it! It's not worth pursuing when you can't find enjoyment in what you do, after all.
:,( I never really liked drawing a lot i all ways saw it as work. doodles are more fun, You don't use any guide lines at all because your just doodling. And determination, i guess one could say i run on it, I kinda wanna be a Mangaka, my older sis says at the rate i'm going now i could be able to make a manga by the time I'm 14. And i do work really hard, i make at least one drawing a day, i can't sleep at all unless i draw some thing that day. But i have a hard time seeing it as fun, how does one make it fun?
Ryuuen, this is amazingly well done(i love how you drew some of the characters from Attack on Titan ) also the original drawings are epic, keep it up please~! your work on anatomy is incredible ;_____;/