I've been messing around with etching for a few months, and I've had quite a lot of luck with a process using a steel plate, a salt-water electrolyte, a power source at 5V or lower, and either a lacquer resist (for WB style relief etching) or a hard wax resist (for traditional etching), then taking a print by putting the plate in a frame, adding a sheet of aluminum gauze, then filling the frame with plaster.

The plaster expands slightly as it sets, so it takes a good print.

The process is not quite as straightforward as the traditional methods, but is much less poisonous, produces no nasty waste products (some clhorine gas, but not much), and doesn't require access to a press.

You can also use it for etching aluminium, which is kind of interesting too. Don't try stainless steel, it doesn't seem to work and you end up with chromium oxides everywhere.