I do basting a lot like Sewnoma and Madame Kelly.
I have found I like it better if I put the glue onto the batt. Then after I have the back lined up, I use my iron and press most of it. It doesn't matter if I miss a few spots, but pressing holds everything in place right now.
Then I can turn it over and put the glue on the batt again, add the top and press. Then it can set for a while or be quilted right away. If the glue has been pressed, it's probably dry enough.
I try to do this process on the large banquet tables at church or at the library. That way I can pin the centers of all three layers right away, lift up one end, glue about a third of the way down, flip down, smooth and iron. Then lift up that end again as far as it has been done and continue on the next third.
When that half is done, I have to turn the whole thing around so that the un-done part is facing me. I have my iron plugged into the outlet near the kitchen serving windows, so that makes it closer for me.
Now I can flip the entire sandwich over and start the other side. I can get this done on a king size quilt in less than an hour. It's the ironing that takes more time.