I'm sure Ed will tell you otherwise, but C41 35mm development is SO cheap at the minilabs that it's probably not worth it - for $5 I can get a film dev'ed AND printed. Even if you just treat those as proofs, and print again at home, it's still not worth the bother to do it yourself in most cases (though of course there is stuff you don't want to put through the mini-lab for various reasons).
I am not going to disagree, Developing C-41 at a Mini- One-hour Lab is most certainly cheaper.
I do not develop C-41 for "cheapness". True, there can be "sensitive" content (I shudder to think of the teen-ager with raging hormones hovering over the "print another one button", with some of my inevitable "less delicate" nudes- the ones I DON'T print).
However, the *most* important consideration is quality. The "one-hour" machines CAN produce decent quality negatives and prints *IF* operated with the same attention and care that we would use in our own darkrooms. For the most part, thy are not. Chemistry is not replenished or replaced when it should be - to do so would cost more and reduce profits - cleanliness has been IMHO abominable... To tell the truth, I don't even consider most "mini-lab" processing to be accurate enough even for "proof" work.
I can remember one roll of 35mm brought to me by a student: When pieced together, it was the strangest combination of both over- and underdevlopment - all on the same roll - I've ever seen. It looked like a barber pole. I've talked to mini-lab operators since ... and they can't understand how it could have been possible. On top of that, some of the "cutting" was bad ... not through the margins but through 20% - 30% of the frame.
She went back to the Supermarket (!) and complained. They were most apologetic, and complied with their contract. They gave her a replacement roll of film.
Did you ever notice that when someone complains about crappy processing, they will always blame the camera, or "you didn't use Kodak film"... or "You don't know much about photography, do you?"
I once was at a small, local camera shop in Maine ... standing next to a girl who had a set of color prints spread on the counter. All of them with a *HEAVY* cyan cast. The SLEAZE behind the counter was saying, "The color is off because you used a Nikon (which they did not sell). If you used a Canon (which they DID sell) it would have been much better." Etched indelibly in my memory.
So, my C-41 processing - Careful mixing of fresh chemicals; I do "one-shot (more expensive, but worth it). Careful attention to time and temperature (JOBO CPP-2). Gingerly squeegeed - lightly and carefully, and air-dried. Very rare to have scratches or inclusions. It doesn't get much better.
The latest ... In the one-hour mini labs, color developing is done in the usual processor. Printing, all the printing, is *digital*... leading to a lot of comments that, "My digital photography is `just as good as the stuff I shot on film'".