Prism99

I don't machine quilt from the center out; I don't want to have to tie up all those loose ends!

Quilting from the center out is probably most appropriate for hand quilting with a hoop. This is because of all the times you have to hoop, unhoop, and move the quilt around, all the while snipping basting threads in the area where you are working.

Machine quilting provides options that make quilting from the center out unnecessary, although it's still an option. For one thing, you can heavily starch the top and backing before layering. This stabilizes the fabric so it is less likely to stretch, distort, or pucker while you are quilting. Spray basting allows all three layers to be in continuous contact with each other, increasing stability of the layers and providing additional protection from having the fabric stretch while you are working. Glue basting provides a similar level of stability. Both provide more stability for keeping the layers together than basting stitches (or pins, although pins are usually not used for hand quilting because they provide too many opportunities for thread to catch on them).

For myself, instead of quilting from the center out, I would heavily starch the flannel top and backing fabric before layering and spray baste. If doing straight or wavy lines, I would use a walking foot working from one side to another. The only time I would work from the center out is if I were doing individual quilting designs (for example, standalone block designs). Even then, I would probably stabilize the blocks first by stitching in the ditch with a walking foot. After that, it really wouldn't matter in which order the standalone designs were quilted.

Edit: Especially for flannel, by heavy starch I mean a 1:1 solution of Sta-Flo and water. Flannel benefits from a *lot* of stabilization by means of starch because it is such a soft, stretchy fabric. If the quilt is already sandwiched, you can usually get by with doing multiple layers of spray starch on both top and backing. It won't be as strong as the 1:1 Sta-Flo, though.