I recently started using an Op/Tech tripod strap. One end is attached around the base of the head (actually, around the base of the levelling base) and the loop at the other end goes around all 3 legs (to keep them together). I have the last 2 sections of the legs out slightly so the loop can go around the legs without risk of sliding off over the feet. I arrange it so the head (the heavy end) points towards the ground.
It seems to work well so far.
FWIW, this is with a G1348 (which has no centre column).