I still shoot quite a bit of film and processing has just gotten too expensive for me. Film has gotten expensive enough and if I have to add processing to it, often I'm looking at $20 or more for a single roll.
I've been developing B&W ever since my first roll some 33 years ago. And I've been doing E-6 for almost that long. But I haven't tried my hand at C-41 until a few weeks ago. And honestly, I don't know what took me so long. C-41 is easier than E-6. It still requires paying attention to temperature, but the duration is so much shorter with C-41 such that it becomes a piece of cake. In some ways, C-41 is even easier than B&W developing. Mostly because the developing time is so much shorter.
As others have mentioned a darkroom isn't required. I use a changing bag to load film onto my tank's reels and I use a daylight tank, so the only time darkness is required is when rolling the film onto the reels. The rest of the process only requires a sink and a few other tools -- a good thermometer, obviously, a 1 qt or 1 liter measuring cup, a funnel, something to maintain a bath's temperature -- a styro cooler for a 12-pack works great for this. I also use a graduated cylinder, which I find makes it easier when it comes time to mix chemicals. Mine is 250ml, which I find is a good size for this. Oh, for B&W and E-6, I have a soft sponge for squeegeeing off the water. But -- most important -- with C-41 you must never use a sponge. The emulsion is still very soft and can be damaged even by a soft sponge. C-41 kits contain a stabilizer, which is used last, and which is supposed to contain a "sheeting" agent, which causes the water to slide right off without spotting. Unfortunately most of these kits contain pretty sorry Stabilizers, in terms of their sheeting action. Some people mix Kodak photo flo with their Stabilizer, but the better route is to use a better stabilizer. And the best I know of is Kodak's Flexicolor. It's cheap enough and well worth getting if one has a lot of C-41 to process, as I do. Finally, to hang my drying negatives (and positives), I have a couple of pants hangers -- you know, the short ones with a couple of clips for holding the pants legs? Well, I use the clips to secure one end of the film strip and clothes pins as weights. You don't need those big heavy metal weights. Clothes pins are heavy enough. I usually hang my drying film somewhere in my bathroom. The tub's shower curtain rail works well.
So anyway, that's how I do it. YMMV.
Oh, and, with respect to 35mm, once I have the dried film strips, I digitize the images with my digital camera and a dupe rig I've put together, with a Nikkor 55mm f/2.8 macro lens at its core. Now, that's a topic for a thread or two by itself. But I do this because if I want prints made, the easiest and most economical way to get them done is to take the images to a processor that can produce prints from digital files. Now for 120, I use my Epson 4990 flatbed scanner to digitize the images. Its resolution isn't good enough for 35mm, but it works very well with 120 and 4x5. I usually take my image files to Costco. They have one of those giant Epsons that actually does an excellent job -- certainly for general prints. If I'm after something of a more exotic quality, I take my negs or positives to a pro lab. In my city, there is one pro lab left. They do very good work and I can get most any sort of print from them that I can think of. They stay busy and I hope they always will.