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Following on from Mark Drela's excellent instructions and the work done by team Spectre (Terry and Simon) I've had a go myself.

Basics:

The Mandrel is a Carbon/Graphite golf driver shaft, smeared with Vaseline (Petroleum Jelly) as a release. Then wound with VHS Video tape. It's important to get the Oxide layer of the tape facing away from the boom lay-up or it will stick. (Terry also found recently that stretching the tape past it's deformation or yield point caused it to bond to the boom, so watch how tight you wrap the boom).

The mandrel is held in a jig for winding and a few pictures of my jig are below. The handle must come off the jig for rolling the lay-up on and it's best to make it easy to mount the boom when you are panicking about the lay-up. (Click on any picture for a full size shot)

The lay-up materials:

The boom I was trying to make is for a competition DLG and so I wanted it as stiff as possible. To this end my boom has two layers of 125gsm Uni-Carbon held on a 45/45 36gsm Kevlar carrier, with 2 additional 5mm Uni-Carbon stiffeners each side. The parts are wet out over a drawing (using a thin Mylar sheet as both protection and as a carrier for the next step)

Wetting Out:

The procedure starts with the Kevlar carrier being carefully aligned to the drawing and then wet out. Then the carbon pieces are added (I use 4 segments to keep as much carbon running down the boom as possible).

Finally the thin stiffeners are added and again wet through

Blotting Off:

The lay-up on the carrier is then moved to the hot-box where it is covered in a blotter layer and bagged for 15 minutes at 60 degrees C to remove excess Epoxy and stabilise the cloth layers.

When it comes out the bag it looks like this and has a soft toffee consistency: I peel it off the carrier at the stage, then lay it on the clean back of the carrier to roll onto the Mandrel.

Roll your Own:

Once the cloth is rolled onto the Mandrel, the assembly is put back in the winding jig and a layer of VHS tape wound over the out side (sorry no pictures of winding as I was single handed on this one, winding is best done with a helper!!).

What next:

The boom is then cold cured for 24 hours (i.e. room temperature). At this point it should slip/twist off the Mandrel and the VHS Tape Layers can be carefully peeled away. It then needs 16 Hours in the hotbox at 60 degrees C to do a final hot cure. Once done it gives a ringing sound if tapped on the bench and is nice and stiff..... Weighs approx 17g.