I started in April 2007 after reading an article on davec101's cyanotypes. After learning traditional cyanotype was only two chemicals, I figured that sounded pretty simple. I used mostly 6x9 negatives from a Brownie No.2 camera. I tried enlarged negatives onto panchromatic film (as it was cheapest at the time), I now do some enlarged negatives occasionally on APHS ortho litho film but I mostly use my 4x5 camera now. I've tried Van Dyke Brown, anthotype, physautotype and gum printing. In order of what I've worked with the most, cyanotype, physautotype, van dyke, anthotype and gum printing. I'd really like to get more into gum printing but I want to do tri-colour/gum over cyanotype. It's a bit more fiddly than just cyanotype though so it's been put on the backburner.
I mostly do cyanotypes. They're easier for me than B&W darkroom. I've not had problems with the paper keeping once coated (no fogging) so I can coat quite a lot then just keep some around, even for relatively quick proofing of negatives. I just need a sink of water for the paper to "develop". I like the blue colour and high contrast of cyanotypes.
I think I kind of explained why I do alt process above.