In Digital Art, one of the most important things is Line Art. Line Art is when you outline your drawing to make it stand out! Although I am just a beginner and learning more and more each day, I am practising every day to get better at Digital Art and Sketching.
Tip: When you add colour to your drawing, you want it to match your character. If your character is not made up get a reference photo and use the colours from there, but if your character is made up think about the personality of your character. If it is sad use darker shades, if it is happy use brighter shades. This should help you determine what colour you should use!
Down below is a video of me doing the Line Art of my sketch then colouring D.Va from Overwatch. Hope you like it!