you need more contrast to this drawing like you need to shade more the black parts of the face work it on and you will understand how it works ;)
Check out some of my work and feel free to criticize it :)
https://scontent-mxp1-1.xx.fbcdn.net/hphotos-xft1/v/t34.0-12/12023022_540551006102231_1677652109_n.jpg?oh=f8f9b4797f40df64a6a8aa18acdaa4de&oe=561EFFA5
https://scontent-mxp1-1.xx.fbcdn.net/hphotos-xpt1/v/t34.0-12/12166782_548338015323530_1309075515_n.jpg?oh=9e6c828e279d048016f667de1b940e1a&oe=561F3721
https://scontent-mxp1-1.xx.fbcdn.net/hphotos-xat1/v/t35.0-12/12164805_548346555322676_209321260_o.jpg?oh=b5783f4a58e53b0b3b1e50654b10daa9&oe=561F1CD8
sorry for the bad quality photos
