Good tips, nice video. Thanks for posting.
I do think it's useful to many and not "duh" because, as they say, common sense is not so common!
I agree with @P1et that to get the best of the two bucket method, you need grid guards in the buckets. At least in the dirty bucket, but I use one in both buckets.
Another pro tip is to fill up two additional buckets and place the buckets at the 4 corners of the car, and walk your hose around the outside of the buckets. This helps keep the hose away from the car and from accidentally hitting your paint as you walk around to different parts of the car.
Also +1 on the foam gun suggestion, I use this also and it is awesome.
Finally, for me, I like to feel every bit of the car, know where the rock chips are, etc., and get the dirt off that is particularly stuck even after rinse and foam. I find that a microfiber glove cloth is great for this, as you run your hands along the car to wipe it and can feel tiny bumps as you go along.
I watched the awesome tutorial series on YouTube by junkman5000 and have been using his system, which is where the above ideas come from and they've worked very well for me.
After 1.5 years and about 26k miles my X6M still looks brand new, inside and out.
http://www.xbimmers.com/forums/showthread.php?t=940190
Edit: forgot the final pro tip - when (if) you take your car to the dealer for service, make sure they put a big "DO NOT WASH" sign on your mirror/dashboard. I drive my SA crazy but she knows - and likely everyone there by now, also - do not wash the Superman X6M, lol! I usually remind the guys, too, when picking up the car. They can radio and make sure it's not getting washed.