IMHO, it's better to be a cowboy and reluctantly follow 'best practices' for the most part, than to be a 'best practices' person and be unprepared to be a cowboy when it's needed.
Sometimes, the best way forward is to force an update on production, even if the only method you have is modifying the executable on disk, while it's running. It's mmaped, so you can do this. But you wouldn't know this if you hadn't broken production by using cp instead of install to update a binary you wanted to modify for the next load.
Putting a site live just involved FTP-ing the files up to one our shared webservers.
We wrote a system for a client once. And there was a particular functionality that I had to iterate over quite a bit, trying to nail down evasive, frustrating bugs.
Needless to say, later, when the client was printing out some invoices and discovered one with several notes reading "F** F** F**!!!!", we got a phone call. We, clearly, didn't managed to scrub the DB properly when we installed it. We were graced by the fact the clients children were in during the weekend, and they felt maybe one of them had managed to add commentary to the data. "Yea! That's what it was allright! It's all fixed now!"
Anyway, software never forgets. Version control is forever. Be gentle when adding commentary to code.
I ended up making the front page panel of the new team twiki page where we had the team structure laid out a small random chance of showing the bulldog licking the screen in a full screen mouse-over, then I completely forgot I'd done it and went on vacation.
The boss was demoing the new site to the global team, with our MD there, and moused over it, triggering the screen licking gif, then moused off it and came back and it wouldn't retrigger and couldn't work out what had happened. It caused bit of a stir, but I was allowed to leave it in place with a very low chance of appearing.
I had a habit of hiding my face in little hard to spot places of sites I worked on in very low contrast. Over my five years there I worked on probably hundreds of sites.
A couple weeks after I'd left for my new gig, I get a message from a coworker that a different coworker had pushed up an untested change that broke the navigation on one of their biggest clients. The HTML had become malformed in such a way as to make the entire page a repeating pattern of my very low contrast face, which had been hiding under the navigation.
The client thought it was some sort of hack. My friend and coworker knew what I'd been up to and explained to the team. I have no idea what was said to the client.
A couple weeks later it happened again with a different site. Same developer pushed bad code and my face hidden under the contents of the page were revealed.
They ended up going on an Easter Egg hunt and removed most of my hidden faces.
It's not something I would do these days as it's very unprofessional but I still get a little smile thinking about it.