Making a DIY wormery is easy. I found two cheap plastic basins the same size – you can use plastic crates from any DIY store or car boot sale.
I first drilled holes in the bottom of one basin to allow any liquid to drain out. This can be collected in a tray and diluted 1:10 and used as liquid fertiliser. Four holes were then drilled in the sides and raw plugs pushed through to hold the top basin in place. I guessed the height of this, but think it needs to rest on the compost in the lower basin to allow the worm to migrate. Larger holes were drilled through the base of the top basin, to allow the worms to pass from the lower to the upper.
The idea is that once the compost in the bottom container (basin) is ready to use the second container is added. Waste is then added to this and in time the worms will migrate upwards through the holes, leaving the bottom container with the compost worm-free (more or less).
I put a piece of old carpet on top to help keep the wormery warm, then covered this with a lid to keep rain out.
Overall cost was £3.90 for the two basins, although I could probably had got these for nothing if I'd been less impulsive. Worms cost approximately £10, including postage, for 250g Tiger worms (Eisenia fetida) or Red Wrigglers (Lumbricus rubellus) are the ones to go for.