How to pass someone on the interstate in our ms3's

If your going to pass someone on the interstate with our cars (doing 75 mph in 6th gear), what gear do you guys drop down to? A friend of mine told me to drop down to 4th skipping 5th gear. Does anyone do that or do you guys just drop down to 5th. Sorry for the dumb question as I have only been driving a standard for a month now. I'm guessing I should be rev matching before letting the clutch out when downshifting from 6th to 4th or should I just drop the clutch immediatly? I'd like to get more input from you guys before trying it. I looked up shifting tutorials but non of them explain how to pass someone on the interstate (quickly). Oh and my friend can't show me since he's in Iraq now.