An anchor helps reduce stress on roots. Near base secure it in opposite direction. Also will prevent it from slowly pulling itself out of the soil or lurching toward edge of put as it pushing through the soil on an angle from below the surface - not optimal, definitely tear some roots when that happens.
When you bend it over, you can gently weaken the stem in 2-3 locations as low to the substrate as you can. This will also take a bit of the stress off the roots and help create a more horizontal result. You essentially shape it before you even tie it down (in both directions). Any growth below the bend should be pruned off as it will suffer greatly compared to the rest.
Just keep moving the tie forward as it grows. If long enough to warrant it, you may need a second tie-down to keep the branch from arching upward.
I say 'weaken' but i cannot stress enough to be gentle. this is nothing like what is done for HST where you break the stem to make it horizontal. You don't want to damage the vascular tissue, but a minimal amount is not a big deal. No snapping, for sure. I just bend between thumb and fingers off-on a few times, then move up slightly on stem and repeat. From there try to bend it across both points to be mostly horizontal. It should provide little resistance to the tie-downs, initially.