I have appliqued a lot of quilts and think it is easy...but do advise practicing first. I often try different stitches before I pick one for a particular quilt. Sometimes I do a satin stitch...some times a blanket one...or others...depends on the effect I think works for that quilt. You do all the applique before you sandwich it...then you have to figure out what quilting will work for the project.
For painting on fabric...for shading I often dilute the paint to get the appearance I want. To shade I use a flat brush and dip it in the main color and the just the right edge in the shading color and brush on a paper to blend...just a little and then paint the fabric...hope that made some kind of sense! I bet if you google either of these you will find better instructions.