If you draw a yellow block, you can ect. draw a border around it with a darker yellow, it does it look more profission.
For computer animation, I would preffer UFX, that you can download free here.
Step 1: New image, set size to 32x32, that's a single tile.
Step 2: Go in generator, choose a style and make it.
Step 3: Now spiff it up via transform, make it different
Step 4: Go in colors, and change color to something cool.
Step 5: Now go to the last menu, and take stampless tile.
Step 6: You now made a good tile, copy and paste, if your pattle isen't build for it, it can loose some of it's quality.