Remember to stay down through the shot. A huge problem with alot of people using western grips is that they try to be flamboyant like Guga and jump up and fall back when they hit their strokes, causing them to shank and mishit the ball often. Set your feet, and make sure your body weight is moving forward. Keep that head down through the shot as well. Also, resist the urge to use alot of wrist on your fh, as it will also cause mishits. On high balls, remember to follow through over your shoulder as you hit through the ball, not down across your body. Stay down and really whip low balls, or they will fall short.
The most important thing to remember when hitting a western; swing through the ball. Do NOT fall into the trap of swinging on a completely vertical path. Yes you will get alot of spin if you do this, but the ball will have no penetration and will feel soft to your opponent.
That's what I can think of off the top of my head(I've been using a western grip for a while.)