Tools
Bonzai Tree
(My First Ever Drawing) Lui Caliber Playing On A Gameboy
(Remake Of) Joji - Unsaved Info Album Cover
I think it would be a great idea to check out some stuff.
http://drawingandpaintinglessons.com...Objectives.cfm
Here's a good site for some lessons on some important things that could make you a lot better at what you want to do.
I'd also suggest you to sketch before you put your permanent ink down. That way, any mistakes you might do are of no harm to the final work.
I also see that your drawings lack some detail. There's no borderline in between objects and it makes it quite puzzling to enjoy looking at your work.