If you're smart and impatient, you can figure this out from the picture. If you are neither of those, or just want to be edified or entertained, feel free to read on.
This is my instructable, there are many like it, but this one is mine.
This guide applies to three of the larger truths I have discovered along the course of my cognitive existence:
Water is seldom too hot...
Music is seldom too loud...
Beer is seldom too cold...
...Especially when you're in the shower.
There was a time long ago when Monks got so tired of drinking water that they invented beer. These monks most likely took showers. My guess is that if they ever drank beer while in the shower, they were probably annoyed by the fact that it usually got some water in it. We can be almost certain the shower beer holder was invented shortly after.
For the past eight months I have been touring Asia with a Broadway musical. This has introduced me to many things:
Korean BBQ, how to sit cross-legged on a hardwood floor without getting uncomfortable, the proper way to sell electronics, and, most importantly: the astonishing lack of beverage holders in hotel showers.
I noticed many other things in life that could use changing, but I'm starting small, with the beer, and the shower.
Step 1: Require a shower.
This is not such an easy step to complete. To properly enjoy a beer in the shower, one needs to require showering. The easiest (and most fun) means for accomplishing this would be to take a page from five year olds everywhere and get well and truly dirty. Another method is to be stressed out and/or tired. This is by far the least desirable way to render yourself shower worthy. If you work in theatre, a load in will fulfill that first requirement nicely. Should you find yourself clean, unstressed, yet desiring a shower, I suggest finding a mud puddle and doing the mud puddle thing.
I could go into long and complicated mathematical proofs that help to illustrate the enjoyment coefficient of a cold beer in a hot shower with loud music, but I won't. The dirtier, the more tired, the more stressed, the more enjoyment to be had from simpler things like cold beer and hot shower. You needn't worry, this is shower, and this is beer. You'll know if you need one.