For most of the musician who have just started or have been playing for many years , one thing is common ie most of the musicians starts with a cover of the song that they like and can play asap , I mean I don’t wanna see or listen to a band who has just started and trying to cover TOOL or OPETH that is too early, you can’t pull that off asap, but as a matter of fact you can cover Nirvana easily if you have just started, so always remember choose the right battle.
When you are doing covers live it is really important to do justice to them because people have heard these songs a lot and they love it , so jam atleast few hours each song and give more then 100 listens, then automatically you will see that you will be a beast on the stage.
Internalize the set list by listening to it a lot of times and then visualize it live for few minutes with your eyes closed, this will help you enhance the productivity during the jam sessions and live performances, visualization helps in training both the muscle and the virtual memory to synchronize well during intense live acts where things can easily go south.
Try to get all the information about the song , listen to multiple live sessions and develop a feel to it , the more you can connect with the song the more vibed performance you can deliver on the stage. Layer out all the instruments while listening, try to start with the drums, observe the tempo , then rhythm and then check out the bass line, try to observe the bass and drum sync, then gradually unfolds all the instruments and try to do these abstract listening sessions quite few times as it will render a way more clearer and multi dimensional picture in your head.
Listening to multiple covers will help you to understand how flexible you can be with your covers and still get accepted by the weird cover audience , yes I mean if you even listen to few covers it will give a clear picture about how many view you can get , what kinda audience , their response and so much more vital information that you can leverage to ride in the growth trajectory.