Very jaundice, very blurry. You should try to work in solid brushes and block in color shapes. You might want to read over and do some of these tutorials, http://www.gfxartist.com/features/tutorials (Digital painting tips, tutorials and techniques) As well as give these a look, http://itchstudios.com/psg/art_tut.htm (VERY…
Best thing you can do is to stay away from detailing imo, you'll learn more from doing 10 faces an hour then just 1. Look at the tutorials posted by vig (you already did I know), and just try to get the base colors, lighting and shaps right. If it doesnt look good in a "crude" sketchy state, refining it further usually…