Many golfers can not get into a proper set up position and posture because their hamstrings are too tight to allow the straightening of the back, so before you tee off or practice work on stretching out your hamstrings so that you can work the golf swing properly around a straight back
Tightness in your calves, hamstrings and buttocks can hurt your golf game by leading to a straight and upright posture
Place a cone behind you and practice your takeaway just trying to nick the top of the cone, if you hit the middle you are too far inside and if you take it back over the cone then your takeaway is going outside