I just made one using Sharon Schamber's advice.
http://www.youtube.com/watch?v=4LGbXou_u4c
The only thing I did differently was I used a home dec fabric from Joann. I thought it would be fun to look at when I'm pressing. I bought a precut board at Home Depot 24x48" x 1/2" thick to keep the weight down and I love it!! By getting the 1/2" thick board instead of 3/4" it isn't too heavy for me to move from one room to another as needed. Sometimes I use it in my sewing room and other times I put it on my kitchen counter.