I taught a couple coloring classes in my home this week. I am not an expert but I shared what I know. We did three cards with three different techniques. The cards themselves are pretty simple so the emphasis could be on the coloring itself.
The first was using water color pencils.
The second card was done with odorless mineral spirits (OMS) and colored pencils. It is important that the colored pencils are waxed based but luckily most are. In this technique, you color the picture with colored pencils. You don't have to use a lot of color or create a smooth image because once your are you use a nub dipped in OMS and blend the colors. It makes the colored pencil much bolder colors and smooths & blends the coloring. It is kind of amazing how wonderful it can be. I think I will do a post with a before blended and after blended pictures. It's a great inexpensive technique with amazing results.
The final card was done with Copics. I used E00, E11, E02, R83, RV34, YG63, YG67, Y11, Y15, C1. I love my Copics because they bend so well. I also love the skin tons you can get from Copics. There are some amazing tutorials online already so I will not spend much time on this technique here.