fyi, I am a sewer and also do ergonomic evals for work. I recently did a presentation at my local sewing store on sewing ergonomics. The proper cutting table height, ironing board height, and big board height should be set at your standing hip height. To find standing hip height, stand and bend your hip by raising one knee slightly. Place your fingers in the bend of your hip. That is hip height. Have someone measure the distance from the floor to your finger tips at hip height and that distance should be the height of those work surfaces. Once set, you should feel a big difference in reducing back strain and pain from inproper bending and stooping. The bed risers work well to raise heights in most instances. Those can be purchased at Bed, Bath, and Beyond or Linens and Things I understand. Hope this helps.