I began using Harriette Hargrave's method of basting a large quilt on a table that is smaller than the quilt. I found a video that is similar:
https://www.youtube.com/watch?v=jnke_KzeTI8. You have to find the center point of the top, back and batting by pressing creases, then line them up on the table. You can create bumps on the table by taping toothpicks or skewers, which I did for awhile, but now I use my old cardboard folding cutting board with grid lines. I can easily clamp with binder clips on it rather than a table top.
I have tried both safety pins and thread basting. I found that prefer Sharon Schamber's herringbone stitching referenced in the previous posts, but with this method, I pin off the quadrant lines before I begin basting.