I've been adding colour to my images to lift them a little and give them a bit of depth. I tried doing this in several ways:
1) Coloured strokes. This just looked tacky and unfinished. They didn't combine with the black lines as I thought they might, instead they just stood out really obviously and drew attention away from the work as a whole.
2) Gradients. This technique worked a little better than the lines. The block colour is a lot more effective than the lines. I have been using reds and pinks to fade into white.
3) Mesh tool: This technique is very similar to the gradient tool, only it allows for more layers. However given that I am only wanting one or two colours I am not sure if it will make a lot of difference?