I want to increase my hip flexibility to improve my arch when benching. I already stretch them daily with the warrior lunge stretch. Is there any thing else I could do? I also thought about going to the gym every day and working on my set up. Thanks a lot.
Practicing your set up and even taking an empty bar and doing reps with it, trying to manipulate your body to get the shortest range of motion, for maybe 50 reps every day is the best way to improve your set up.
Stretch lying backwards over a stability ball. Move your hips around to gain mobility not just stretch the hip flexors.
Get on bench and practice set up. When I moved to a wider foot stance it helped me, but I am a foot flat IPF bencher. If you are on your toes, practice the closer stance. When you feel good put a board under your ass and set up again. If you can get your set up with 4 boards under your ass you will be flexible enough for BP.
Set the pad on a GHR so it hits your kidneys when standing in front facing away from the GHR. Now arch backwards over it while keeping your feet flat. No explanation required here.
Check out a chunk of the Cressey-Robertson articles, they address a lot of the issues you’re running into. These are the last parts of the articles in question, you can pick up the links to the rest from there. They really really helped me.