Chalk up one more vote for the walking foot. I used to think it was just for quilters, but when I made my first fabric purse -- with the fleece batting, lining, top-stitched seams, mitered corners, etc etc -- I realized there was no way I could get through it without the foot. Best $25 I ever spent. Most of what I sew is pieced and embellished, with up to 25 different fabrics (and seams) in one piece, plus additional layers. But I also use the foot for heavy upholstered cushion covers, tapestry jackets, etc. Definitely worth the investment.

Here's another vote for the walking foot. I used to think it was just for quilting, but now I wonder how I lived without it. Most of what I sew is embellished and pieced, which means there is usually some kind of fabric "sandwich" involved and many different types of material (tapestry, velvet, jacquard, etc) in one project. The walking foot adjusts easily, and makes collage projects, fabric bowls, etc go together faster. I have also used the foot to sew slipcover cushions out of a heavy Ottoman upholstery fabric, and right now I'm sewing my son a pair of twill skateboard shorts with loads of cargo pockets. The layers of fabric feed through beautifully -- much smoother than if I used my all-purpose foot. My machine is a Necchi, and the foot cost around $25. Definitely worth it!