When we bought the house, there was no sink in the basement. Most importantly, you need a water source. We had the plumber install a slop sink. Since our water pipes are high up, we had to also install a pump to the sink drain to pump all drained water up to the exit pipe. For most of you, that will not be the case.
We had a big island in our small kitchen We had it cut down smaller and saved the top counter piece. With this my husband built a work table for me. This is where the printing and processing is done. The darkroom materials were given to me by my sister. She no longer does analog and the equipment is at least 15 years old, but it still works. This includes a less expensive - but no less capable - Omega enlarger, printing easel, contact proofing frame, four trays, tongs, steel reels and tanks for 35mm and 120mm film, film squeegee, print washing tray, funnel, graduates, bottles for chemical storage, and old clothes pins for hanging film.
Under the sink, I put a shelf to hold the chemicals, graduates, funnel and other things. All mixed chemistry is on the floor in plastic light-proof bottles. I used to use Kodak - still have a couple of bags left - but tried Eco-Pro to test it before switching the PV darkroom. I liked it and only will buy that from now on. It is safer for the environment and I like the results.
I no longer buy 35mm film in individual rolls. I roll my own film using the snap caps I bought when an undergraduate. I use Ilford HP5. I do buy my 120 film for when I run out of what my sister ofloaded. I have some expired Ektar that is a lot of money to process as it is colour. I also have some Tri-X and Plus X left over from my sister. Holga just started making film and received a few rolls of that as a gift. I cannot wait to try that out!
I have no changing bag. I sit in my bedroom closet, put a towel at the bottom of the door and put the film on the reel in the dark. To darken the basement, I scrounged around for opaque black fabric. I sewed it up to double it and then added sticky velcro strips. When printing, I velcro the fabric to the two windows and the door glass to keep the light out.
As extra inspiration, I am including images of my workspace in a bedroom in our house. I have a drafting table that I use when making books, small scale sculptures and working on altering my photos. Most supplies are stored in a cabinet from my Grandma's house, under the work table and in the attic. I keep fabric, toy cameras, metalsmithing tools, and other odds and ends in the cabinet. Oil paints are under the table. I also have little storage containers about the room. It may not make for the neatest room in the house, but I find new ways of reorganizing it occasionally. The most important thing is that I have all supplies readily available for when the mood to work strikes me.
And yes, that is the one and only Millie, inspecting the supplies. Now go out and make some art!