See, I don't know how to sew all that well either. What I did sew (on neoprene) on my pants was button holes (by hand) and a test welt seam on some neoprene with my sewing machine. Someone suggested stretch denim because it has some stretch like the tricot and, denim is kinda thick like the neoprene. It may not have 4 way stretch, but is at least something that is closer to the real thing than any other "cheaper test fabric". I know it would not be as cheap as muslin .99/yard, but is at least similar in 2 respects, it stretches, and is thicker than plain cotton, lycra, nylon, whatever. Not nappy like wool though. The first thing I would do, is really rough draft a pattern in .99/yard muslin. Then, use the denim as your Final before using it on your neoprene. Or, if you can get enough test stretch denim, then you won't have to tweak your patterning as much as you would the muslin. Several stitches you want to consider practicing, are especially your welt seam and serging stitch, and a top stitch straight. (Test on muslin or denim first) Get a feel for your sewing machine and what it can handle, then test a piece of the denim. It's best to use an industrial machine. And be aware, if your home machine can't handle denim, then it can't handle the neoprene. Some machines just don't have the power. 9 oz per yard of weight I believe that is what you mean. See, leather works similarly, except, it is a solid density rather than porous fabric materials, therefore, you can actually calculate how many mm/inches thick leather is. Fabrics that are porous have too much give to give an actual thickness are measured by weight only. You can asume that the higher oz per yard means more dense material, but won't be able to measure the "thickness."
The only sewing I've done since those 2 things on zam, was a christmas stocking for my son, and a tie for my son. So I am very close to sewing newbdom as most newbs.
