Pin it a lot. Better yet, use seam tape too. Go slow when sewing it and get your thread tension right on scraps before staring. It doesn't take much tension when sewing this material. Don't pull on the material either as it feeds. Let it feed naturally. This is were seam tape helps tremendously. Remember, the seam is hidden once you turn it right side out so, it will look fine.
Just a reminder to understand that aside from keeping it straight and on course, the machine doesn't need help feeding it. So, if you get going sideways away from the edge, stop sewing it and raise the foot to fix it so you don't stretch the material. Don't fix it by pulling on it while sewing it. that causes a huge pucker factor.
My last tip is once you have layered, pinned, and taped the seams for sewing, sew the stuff with insulation facing up towards the sewing foot. not down towards the bobbin and feeders. That sees backwards but, believe me, it isn't. If you sew it insulation down, you will have huge feeding issues. Face up is the way to go. I promise.