How to create a skewed checkerboard pattern in Illustrator
An Adobe Illustrator (CS4) screencast tutorial including these steps:
1. Draw 2 squares: 1 black and 1 white
2. Turn them into a Symbol
3. Apply Transform effect to repeat them horizontally
4. Apply Transform effect to repeat the line of squares vertically
5. Expand everything and move squares to make 1 perfect rectangle
6. Skew and resize the checkerboard (to match the Bavarian flag)