I had also heard that if you had a longer piece that it should go on the bottom for the feed dogs to ease it in. But that was mainly for sewing garments. Something I rarely/never do today.
In my early days of quilting (the 70's), I didn't know that it worked better with sewing two fabrics the same length and that you pinned them for better results. Instead I would always just cut strips and start sewing. Even though I would iron the heck out of it, I would sometimes come up with ruffled seams. Then a friend of mine, who was a home ec teacher, gave me the scoop that it was better to measure the lengths and cut them the same size, pin, and don't stretch while sewing. The results were nice looking flat seams.