Son't use spray. Use a glue stick made for this purpose.
I took a class once, learned I couldn't sew on the lines of the pattern very well. Don't think I ever finished the little project. My daughter that does not even know how to thread a needle, gets paid for folding paper piecing patterns for a distributor, but I have yet to sew those that I got from there either! But, the one thing I do remember from the class is to remember to make smaller stitches to make it easier to tear off the paper and avoid tearing out your stitches. too late for that tip now I suppose, but might help someone down the road.