I started to do my Live recording with the instruments / gadgets available at the place. I wanted to help my fellow musicians / sound engineers / hobbyist to learn 2 cents out of my experience on live recording. Intially I thought it was a easy stuff to do a live recording. Later I came to know the problems we should understand before getting on with Live recording.
Tip 1:
Always try to maintain the master level in your recording software / gadget between -6 to -4 db. It always helps us to avoid clipping of audio data. It is very hard to restore a clipped / badly distorted audio data.
In my first Live audio recording with the help of 16 Channel Allen & Heath -> USB Audio interface (MAudio FastTrack pro 4×4), I was able to make a good recording of the Live Worship. There were ofcourse some grey areas where I have missed few things because of clipped data.
So always maintain audio levels at the optimum between (-4 to -6 db).
Tip 2:
Try to use a powered public address system if you feel that there are some ambient noise at outdoors. The sound from the powered public address system would reduce some amount to ambient noise from outside.
This idea I gained when I was recording a live worship. It was raining heavily outside. The recording did not happen in a recording studio, rather it happened in a house. because of the Powered PA system the recording went on fine. Nothing wrong in trying it, if you felt that this tip was useful. leave me a comment.
Tip 3:
If padding option is available in your audio interface. Better use them when you do live recording. It may look like your recording volume seems to be very low. When you normalize the audio data then it would become a clean recording.
Tip 4:
For heavy metal, rock music / aggressive vocals you may consider using a compressor / limiter.
As my knowledge improves I would try and update this post 
Happy live recording!