Being on tour all the time gives me the opportunity to see the world and make new friends. Its usually a different city every day and sometimes even different countries. Maybe you know a band, maybe you're friends with a band or maybe you've just been lucky enough to be asked backstage to watch the show. I'm going to give you some pointers to help you not piss off an entire tour and hopefully help your experience.
Step one: Be respectful of where you are. You're basically stepping into someones home, while it doesnt look like one it is, everything has its place. Road cases aren't your coaster, don’t put your drinks on them, dont lean on them, dont set your shit on them. Lids are not trash cans, or drink holders.
Step two: Don't bother the crew if they're busy. Generally if it looks like i’m doing something of any importance I probably am. If im tuning guitars, or changing pedals or basically anything other than drinking Ice Cold Danweisers, dont talk to me. This is not me being rude, this is me taking my job seriously and wanting to make sure the show goes perfect.
Step three: Be curtious: If the show hasn't started yet and things are running smoothly it is totally okay to ask questions. Its nice if you start off with something like this "Excuse me, is there an okay place to watch side stage show that i wont be in your way?" This shows me right off the bat that you value what I do and are just trying to watch side stage. In doing this you've just earned nice points which at the end of the night could probably be traded in for guitar picks or set lists.
Step four: Know where the line is. A lot of times there are things that are okay for some people and not okay for others. This is generally displayed between bands/crews on tour. It might be perfectly fine for myself to walk up to a guitar player and talk with him right before he goes on stage, it might be okay for me to set my drink on another tech's world because we're friends. This does not mean it is okay for you to do such things. Generally the nice rule is don't talk to the band unless they talk to you first. Every band and every band member is different, some like to warm up before the show, others like to have a drink and relax, some like to get into the zone. Imagine yourself walking up to an Olympic athlete right before their gold medal race and asking them for a selfie. This obviously can vary due to your relationship with the band.
Step five: enjoy the show. Everyone is working towards the show so make sure to enjoy it. I recommend taking a picture here and there but never be on your phone the entire time, its rude to the band you paid to come see. I'd much rather remember the show for being there than to look at it on Instagram the next day. Like i said before though, i get it, pictures are important. Just don't forget to watch the show through your eyes not the screen on your phone.