A golfer can swing incorrectly and get away with it by compensating. The more fundamental the flaw, the more exaggerated the compensation. Save yourself some trouble by getting the most basic (and easiest) fundamental correct: your grip.
One way to check your grip is as follows: While taking your grip, place a tee between your hands, positioned so that it's pressed between the bottom of the fleshy pad beneath your right thumb and on top of your left thumb. Take the club back to the top of a normal backswing: the tee should still be in place.
If the tee has fallen out, your hands are separating during the swing. Separated hands let the club wiggle quite a bit at the top of the swing, changing both the angle of the clubface and the swing path.