You will get a million different responses to your question on the different methods we use. I use Hobbs 80/20 fusible batt and iron my sandwich together. I am going to try the 505 spray basting on my next one.
HOWEVER you seem to have the basics for pin basting. The stainless curved quilters safety pins do a good job but can be expensive. You can use regular brass ones but they are harder to put in and close. The only tip I wold add is place a marble under the back of the sandwich before you start pinning. You can roll the marble along as you pin and it creates enough space to put the pin through the sandwich. I use knee pads for crawling on the floor so my knees don't get sore. If at all possible do the pinning on a couple of large tables with clamps to hold the back down and save your back and knees. Good luck.