I use pins-the curved kind. I can't handle the smell of most sprays and my dd has asthma so I won't spray something like that inside. We don't even use hairspray here except for other dd's dance recital and then we spray in one room where no one will be going for a few hours.
I've read about the aqua net but then some said their bigger quilts didn't stay together while machine quilting them so I chickened out. I wish I had a big surface to do any kind of basting-I have to do it in portions. I did see a video about how to sandwich with two long wooden boards so I got the boards and will be trying that sometime.