(Fig.1) Cheap rubbish..
First off I furnished myself with a cheap and nasty 6.5mm slotted screwdriver. You could use a larger one but its likely to need filling or grinding if its to fit in the spoke hole on the inside of most rims.
This is an ideal opportunity to make good use of an old slotted screwdriver with a knackered tip.

(Fig.2) Meltdown..
I wanted to use a wooden tool handle for the finished spoke-driver. So it seemed the easiest and neatest way to get the shaft out of the plastic handle was to heat it (the shaft, not handle!) with a butane gas torch (about £3 from the local hardware store) and pull it out just as the plastic started to melt.

(Fig.3) 3rd degree burns..
The shaft needed to be heated for a couple of minutes before it started to come loose in the handle. Then I just pulled it out quickly with a pair of pliers.
Warning: You don't need to be told that the shaft was hot do you? very hot. SO hot that it scorched my bench-top.

(Fig.4) Naked..
So here's what it looks like with its clothes off.

There was some melted plastic left below the two stamped lugs, but it proved easy to scrape off with a knife and a small file.

(Fig.5) Bump and grind..
The shaft would need to spin freely in the wooden handle (see fig.8 briefly) so those two lugs visible in fig.4 had to be killed off. You have a few options here: file, angle grinder or bench grinder. I had a bench grinder to hand so used that for a quick and smooth finish.

(Fig.6) Bend it like..
precision engineers look away now! The shaft was now ready for the first bend. I heated it for several minutes and smacked it with a BIG hammer until a 45° bend was achieved. (Musson suggests 90°). Try not to knacker the head too much when bending it, but remember that you can tidy it up later.

(Fig.7) The chicane..
(Me granddad would turn in his grave if he saw this bodge). Now I heated heated the shaft again (further along towards the blade by about 25mm) for the next bend.
Once it was hot enough I smacked it 45° the other way (again Musson suggests a 90° bend).

(Fig.8) Like a glove..
The tool handle cost me 50p from the hardware store. I drilled a 6.5mm hole in the end equal in depth to the straight length of shaft furthest from the blade. When the shaft is placed in the handle it should spin easily with very little 'rock' and not catch at any point in its rotation.

(Fig.9) Top notch..
Now to the blade. The whole idea of the spoke-driver is to help you quickly lace a wheel and bringing the spokes up to a 'slack' tension. Following the idea in Mussons Book I filed two steps into the blade to leave a 'point' as shown. This point should be about 2mm long and 1mm wide.

(Fig.10) Rounding out..
The point on the end has to fit easily inside a the hole in a nipple without damaging it (they are often made from aluminium), so I decided to round off the sharp edges with a small (and rusty - oops) file.

(Fig.11) Slimming..
As you can see from the fig. the blade was still a little too wide and I wanted it to be straight down the whole length, so again I used the grinder to flatten all the necessary surfaces and just tidy it all up a bit.

(Fig.12) ent..
So that's about it...
Actually this article is a terrible demonstration of tool making and I only followed Roger Musson's instructions VERY loosely. But it works pretty well and will probably last for ever (relative to my lifespan that is...)