While in college, living in the dorms, I found that the best and most convenient place to get myself off was the shower. I shared a double room with a room mate, and my room is basically just a bedroom with two beds on either side. She's the best room mate ever, and we are both very comfortable and open about masturbation and being naked around each other, but I still usually stick to the showers mainly because I am a very messy squirter and it's easier to just clean off afterwards and not have to constantly change my sheets.
During what I like to refer to as my 'horny week' the week before I get my period, I make it a point to masturbate every night before bed, because if I don't I'll be so wound up I won't be able to concentrate. When I'm done with my day around nine, I'll get my bathrobe on and grab my shower bag. I have one of those waterproof tote-bags you can take into a shower that most people use to hold shampoo and soap and those things, but I use it for something different. I hide all my sex toys in the bag, as I'm already using them mainly in the showers, it's the best place for them. Plus it keeps them together so I never lose them. It's a neat little disguise, most people who see me with just assume that it's full of shower products.
The showers in our dorm are just across the hall, and they're all individual, which tiled walls separating them all the way to the ceiling, which is nice, because it gives me a little privacy.
I usually start by soaking in the hot water and playing with my nipples a bit, usually I'm already soaking wet and ready during this time, so I dip into my bag of toys. Recently I've been really getting off on anal, so I like to start by toying my ass with a thin dildo to get it ready, which at times, almost brings me close to my first orgasm. I then switch to a huge suction cup dildo, that's about eight inches and really thick but a little soft. This has been amazing because what I do is attach it to the wall at waist height, and slowly work it into my ass. When I get used to that, I begin rocking back and forth, butt-humping the wall, which is incredible because I can slam my ass into it as hard as I want.
I can climax very easily from anal stimulation, so I usually just do this for about 15 minutes while rubbing my clit, and achieve countless orgasms. My pussy juices end up just running down my legs into the shower drain, so like I said, clean up is not a problem. Sometimes when I'm in the mood, I'll use a rabbit vibrator in my pussy for some double penetration, it's always amazing to feel the two toys rubbing up against each other in both my holes.
After 20 minutes of this I feel sated, at least for the night, and clean up, put my toys away, put my robe on, and walk back to my room. My room mate knows about my routine, so sometimes when I come in with a blissed look on my face she'll say "have a nice shower", and I'll joke and say "oh yes it was simply heaven"