Definitely use leg drive!
You can add up to 10 pounds or more just by adding leg drive.
When you start using leg drive, if you feel pressure in your head that's completely normal. That means your leg drive is assisting your bench, and you are doing it right.
This has already been said, but I'll repeat it. Its important for overall shoulder and chest health.
1. Tuck your elbows in
2. Use an arch, but keep your behind on the bench. You don't have to get super arched or anything, just a nice easy one.
3. Roll your shoulder blades back, like you're trying to make them touch. This takes A LOT of getting used to, but once you get used to it you'll like it.
4. Drive with your feet. Your setup depends on your height also. Ideally, you want to be flat footed, and driving with your heels. BUT, its fine it you can't do that, and just drive with your tip toes and top of your foot. Try to tuck your feet as far back as you can because this will help your arch.
I hope this helps some.
Keep us posted on your progress RR!