The most important thing about hanging in the wind is site location. You want a spot that provides shelter from the direction of wind. Bushes work great, a grouping of trees, rocks, felled logs, low points on terrain etc..

In terms of your setup, you want your tarp perpendicular to the wind so it hits broad side. The lower and flatter the better. so the wind flows over the tarp rather than catching it like a sail. If you setup parallel to the wind, the wind will turn your tarp into a wind-tunnel and blow away all your warmth.

Another thing that helps is to hang with a continuous ridgeline running underneath the tarp, rather than above it.