Step 1: Get an Idea and Gather Your Materials
Now You'll need to decide what you'll use and gather what you'll need. For this, I decided to use oil paint sticks. Basically it's oil paint with hardener already mixed in, in the form of an over-sized crayon-type thing. You don't have to worry about getting the proportions of paint and hardener right, and these dry overnight.
I used these on a canvas board, and I also had a couple paper towels handy for wiping off my fingers as well as peeling the film off the oil sticks (more on that later).
Step 2: Prepare Your Canvas and Design
I just drew my design right on the canvas in pencil. You don't have to do any special preparations on the canvas unless you've stretched your own, then you may want to put a primer coat of gesso or white paint on so the canvas doesn't absorb the paint.
Step 3: Start Painting!
You'll notice that when you leave the oil sticks sit for a while, they develop a film or a casing on the outside. This is normal and they're not ruined. Simply peel the casing off to get at the fresh paint below it. I use the paper towel and my thumbnail to rub the casing off. It is very much like peeling a hard boiled egg.
I suppose this is a good time to put a warning in here:
YOU WILL GET MESSY IF YOU CHOOSE TO USE OIL STICKS.
This is basically grown-up finger painting. You can use a blending stick (those pointy rolls of paper in the drawing aisle of art stores) if you wish, but why pay for them when you have 10 free blending sticks with you at all times? Using your fingers also helps you feel what you're doing, which allows you to prevent errors before they happen.
Step 4: Add Shading and Highlights
I also used a contrasting color (in this case, red) to add some areas of shadow instead of just using black. It gives a more natural looking color. Again, rough it in, then blend smooth.
As you can see, the edges are not sharp and crisp. This is because you can go over the edges with the colors that appear next to them and give them a crisp edge later.
Step 5: What You Have So Far
What you also have is a very nice looking painterly effect. That's one of the greatest benefits of oil sticks in my opinion. It give you a very good looking surface with very little effort once you get the hang of them.
Step 6: Repeat for All Colors
At this point, it still has the rough edges and there are several fingerprints on the background. We'll take care of that.
Step 7: Cleaning Up the Edges
I wanted the background to be a gradient from yellow to black to create a vignetting effect around the edges. To start, I went around the outside of the heart with the yellow oil stick. Don't try and go right up to the edge. Next, I took a small, sharp-edged paint brush and brushed the paint right up to the edge to create a clean, crisp edge. This is where it helps to put on lots of the paint at once so you have enough to brush around. I went around the entire heart like this.
Step 8: Finishing the Background
I blended using two fingers and going over the "seam" between two of the colors in a circular motion about 1" in diameter. After that, I followed the edge around the entire way slowly blending it until it was a fairly smooth transition.
Finally, to finish it up, I put a little black on my finger and went around the edges so there wasn't a glaring white line around the whole thing.