I really like your abstract pictures, they are all vivid and original.

Your manga pictures are good too, you are quite skilled with both anatomy and facial structure but, even though for practice it is a good idea to use models, may i suggest you trying to do original poses, faces and hairstyles? Especially if you are making your own original characters. Its just, when i first clicked on this thread, i really thought the first picture was a fan art of Chi, I did'nt realise it was'nt until i noticed that you called the picture you drew 'Leita', and explained what you were doing above.

Being original helps you be more confident with your drawings and does'nt limit you to copying certain poses and styles. :3