Live music photography is tough. Not only are you shooting in low light, but you're also shooting in one of the most unpredictable environments. I started my career as a photographer in Vermont as a live music photographer.
My first show was a job at my local fair. I was asked to shoot the rides, the people, food and the concerts. I loved how unpredictable it was and I loved the challenge of only having a few minutes to get the shot. That is why the number one most important tip is to:
Understand the Venue
Every venue is different. Whether you're shooting a local bar venue or a big arena, there are going to be rules, places where you can stand and lighting situations. Getting the most information you can about a venue will give you a better idea of what gear to bring, which can make all the difference.
Know Your Gear
It doesn't matter if you're shooting concerts, portraits or anything. A photographer should know their gear. Having the right gear is essential for getting specific shots. Shooting in low lights will require that you also have gear that has a low f-stop.
Now, if you don't have the right gear then this doesn't mean that you're doomed. I shot my first concert with a kit lense and was stuck between F3.5 - F5.6 so I was shooting low shutter speed. I missed a few shots that I otherwise would have been able to take with an F1.2-F1.8 but since I knew my gear, I was able to pull off a bunch of shots that I love.
Don't Forget the Crowd
My main philosophy going into concert photography is to always remember that this is a show. There is a crowd and there are people connecting with the music and you have the opportunity to capture that.
In terms of getting creative, you can use the crowd to frame your photos or you can show interaction. Most concert photographers will also take shots of just the crowd to set the scene.