I picked up this technique from Rowen as well. Which is why I refer to it as "The Rowen Method" of tailpipe polishing. I also have a fetish for a super clean undercarriage and I do the silencer polish as well. Makes a HUGE difference!
I think everything has been covered. For that chrome effect you will need to follow Rowens method. I picked up the polishing kit from builders which came with the mops and various levels of compounds. Once you have the pipes polished to an acceptable level, I use Autoglym metal polish and top up with Collinite #845 wax for protection and added shine. This step alone makes a HUGE difference.
I find other metal polishes like Autosol etc. a bit to abrasive and they have scratched my chrome tips in the past.
Also the biggest problem most face with restoring tailpipes is that built up carbon crud that sits on the bottom half of your tips.
Most metal polish alone can not clean that up. The best way to remove this is to use a bit of steel wool + metal polish. Rinse and Repeat if necessary until it is completely clean.
DO NOT use the steel wool on the outside of your pipe as this will severely scratch it. Use only on the outer tips!
This is the outcome of a brushed aluminum tailpipe, using the method decribed above: