One of the (many) reasons I am a dedicated film photographer is the tactile element: I like to be able to make things myself, with my own hands. I want to get elbow deep into the process, literally. This is not so much about control as it is about making something organically, and minimizing waste; so, I roll my own 35 mm film. It's a little bit fiddly, and most likely character building, but it isn't rocket science and can be done just about anywhere, even without a darkroom. Here I present to you my very un-scientific, somewhat seat-of-my-pants procedure.
Tri-X is my tool of choice in every format. I order 100 foot rolls of it from whoever is cheapest; usually I have an extra one in my freezer just in case. Re-loadable film cassettes are available online (and in your local brick & mortar if you are lucky), and a lot of the time labs have boxes of empty canisters that they would love for you to relieve them of. Get the solid black ones, with solid colored or black lids, if you can, for light-proofing goodness.
I have one of these daylight loaders, but it's flimsy plastic, wastes a few shots per roll, and I don't trust it, so I will not be covering how to use it because quite frankly I don't know. This doesn't mean it isn't a valuable tool, of course; every madness has its own method.
My first step is setting up carefully. I empty every cassette, line it up with its corresponding innards and lid, and place a piece of masking tape in front of it, so that everything is ready to go. This is an example of how I have set things up on my bathroom sink before (the one room in the house I am able to black out with a big piece of cloth over the door, although my paranoia about film is intense enough to usually make me carry this out at night). You could also set up this way on a table / countertop, and then do the actual rolling in a dark bag; I have done it that way more than once.
The tape will be used to fix the film to the spool, like this
Obviously I am showing the tape affixed to the end of an exposed roll, for practical purposes.
The next step is to get your film in place - you can see it there on the table in the last photo. If you are going to roll the film in darkness, it would need to be out; if you're using a dark bag, put it in there. You will also need a pair of scissors, for cutting the film once it's rolled onto the spool and put into the cassette. These would need to be in the dark bag too.
Now it's lights out time! Assuming that all bulk rolls are packed similarly, inside that nice shiny tin is a black plastic bag, with the film inside. I nest the tin lid underneath, open the bag, turn the roll on its side, and just have the end of the film sticking out, so it's like a dispenser.
With the spool in my left hand, I pull out some of the film, carefully tape it on, and then roll the film around it. My method is not exact, but I usually count about 30 revolutions, and somehow that gives me anywhere from 18-26 frames per roll. (Did I mention this is un-scientific? You have to be prepared for a little bit of uncertainty when you are rolling film this way, but not knowing exactly when my roll of film will end in my camera has never caused me a problem.)
Once I have rolled as much as I want, I slip the spool into the cassette, squeeze it together, and pop the lid on. This is the fiddliest part, and can be a little frustrating / difficult, so I highly recommend practicing getting the cassette back together before you get started. I usually put a thin piece of tape around each end of the cassette, just to make sure neither end pops off if I drop the roll of film. This is the point where you would cut the film from the rest of the roll; I tend to leave about 1/4 inch sticking out.
And that's it. Maybe it takes a little getting used to, maybe occasionally you have a mishap, but it's well worth it in my opinion. Once you get used to it, you can roll your own redscale (flip over a roll of color & roll it back again!), or make your own shorter rolls of those 36 exposure gorgeous CineStill films. The sky's the limit. Get rolling : )