Practice takes quite a lot of time
Practice is a personal task
Rehearsal is done just a few days before the actual act
Rehearsal is a group task
Break your practice time into chunks. Make it varied. Practise your exercises/warm-ups, new pieces, old pieces and try making something up for yourself.
Before every practice session, do some warm-ups (voice), finger-loosening/strengthening exercises and scales as a matter of routine. These prepare you physically and mentally for the task ahead and are very important.
Don’t just play your piece of music through, beginning to end, a couple of times. Break it into sections.
Where are the hard bits in your piece? Practise those bits the most.
Pick the hardest bit (as small as two notes, but no bigger than one bar). Practice it at least 20 times. Now add a few notes before it and after it. Practise it another 20 times. Keep adding more. Practise 20 times….. and so on.
Practise in your head. Picture your fingers/hands in your mind and make them play through your piece.
Sing through your song in your head. Go over your lyrics until they become automatic.
Start at the last bar. Practise 20 times. Now do the last two bars. Practise 20 times. Now the last three bars – and so on.
Practise at super-slow speed and gradually increase the tempo as you get better at playing it.
Play with the backing CD or metronome or rhythm track to make sure you have good timing.
Play it all loud. Play it all soft. Play one bar soft, the next loud, then soft. Then decide which parts should be soft and which should be loud or very loud or moderately loud or gradually softer/louder.
What about the tempo – does it sound good to have a part get faster/slower or to have a pause somewhere?
How will you make your piece sound like piece of music, not just a bunch of notes.
Don’t just practise until you get it right – practise until you can’t get it wrong.
Rehearsal is not practice
Keep rehearsals focused - make a team plan
Rehearse in smaller sections (eg just rhythm section or just vocals)
Practice the starting and the ending of the song (over and over again) as group
Rehearse in different room
Rehearse on camera
Try setting up like you would onstage
Isolate difficult parts - and play through those parts again and again (eg going into the bridge)