Well that was painless, if time-consuming!
I followed the sage advice of having a nice hot shower first, then I made up loads of lather with Real Shaving Company shaving soap and hot water in a mug, slapping it liberally on the fizzer and slopping it about. Then I reached for the razor..
The Merkur is a heavy lump in the hand - a real culture shock after the weightlessness of a Gillette multiblade thing. I started at the sideburns and followed Regulator's advice to not press too hard. I actually found that I didn't need to press at all - the blade is so sharp, and the razor so heavy, that you just let it get on with it.
The sides and cheeks were easy peasy - under the chin proved a bit trickier and I was convinced the razor wanted to chop my adam's apple clean off, but all went well with a bit of care and patience. Upper lip was tricky, but not overly so, and once I'd sussed that stretching the skin with the free hand makes it all a lot easier then it became, well, a lot easier.
To finish off, I lathered up again and ran over the low-risk areas with up-strokes. My chin and cheeks are now as smooth as a baby's bottom.
I have one small nick on the adam's apple, but I had a previous shaving bump there anyway. Overall the finish is a lot better, with fewer red spotty bits.
I've now orderered a Badger brush too - they seem to be the thing to have, and I will have to order some blades as the razor only came with one. Those Derby ones look an incredible deal, although I've read that Feather blades are sharper. I suppose that's a double-edged sword, as it were.
Good stuff though, this is the only way to shave, but I can see me becoming an evening shaver now, as I don't think this could be rushed..