For this design I just used Wet N Wild French White Creme (pictured), black acrylic paint and a thin paintbrush. 

Here's the quick tutorial I put together. I actually made it a while back, during summer when I had nothing to do. 

Step One: Paint your base color. White is the usual color, but you could use any color or mix of colors. 

Step Two: Use black, or any other color you choose, and paint squares at an even space apart. 

Step Three: Paint lines extending from the front corner of your squares as shown. The picture makes more sense than my explanation. 

Step Four: Fill in these lines as shown. Try to make lines as straight and sharp as possible.

Step Five: Paint the leg parts off each square. 

It's extremely helpful to look at a picture of the actual Houndstooth print while painting for reference. This way you can see the shape better. I think the key thing is to go back with your base color and fix any lines that need it. The problem most people have with painting Houndstooth is that the opposite color (white in this case) doesn't really look like houndstooth print, rather weird shapes. If this is the case, be sure to paint over and follow the same steps you did with black, with the white paint.

I hope you found this helpful. Let me know if you try this out!
Thanks for reading!