For a really nice tulle that doesn’t look like netting, you’ll want to avoid the typical nylon tulle. The really nice stuff is silk tulle which might also be considered bridal tulle. You might have to look online to buy this and it might come in limited colors and be pricey. I recommend cutting it with a rotary cutter to get it more even. With scissors, I always end up with edges that look sloppy. On the number of layers, it depends on how full you want the skirt to be. To give you a better idea, the skirt on this blog used 6 layers (https://bowtiesandbaubles.wordpress.com/2013/02/06/diy-anthropologie-karinska-tulle-skirt/) I probably wouldn’t use crinoline, just add more layers for a fuller skirt. Crinoline can be very scratchy again the skin unless you have a another fabric between it and I don’t think you’ll need it if you’re using tulle. Maybe just use a silk lining. Hope this helps.