I now quilt on a long arm, so I need to do it a little differently, but I also mark the centers of the top and backing and batting. I pin the three layers together at the center and baste from the horizontal center down to the bottom of the quilt (on the frame!) then roll back to the horizontal center and baste from the center up to the top. I use Superior's VANISH thread for basting with about 4 SPI, and those stitches just wash out when the quilt is laundered.
It's a little tricky to do, but I've been pretty successful with several quilts by doing it this way.
Here is the BACK of my "From the Heart" quilt:
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And the front:
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