if you are JUST having line troubles, and you have already begun blocking, leave the blocking for the moment for concentrate on getting lines down pat- it's easier to block and mess about on stage when u are cruisin with your lines.
tricks i have learnt along the way include...
walk around, as said before, while doing your lines. not necesarilly as you have blocked your piece, just wandering. moving about gives your memory more for some reason. read through with script in hand, looking up and down to it when you need it once, or twice if u think u need to. then put it down for a few runs, keep wandering around. around your house, around the school halls, everywhere. mumble it under your breath as you drive (if you drive) or on the bus.
another good one is, while you are walking, chuck a ball or something up and down. the extra movement also gives more identity to the lines and makes u remember them. it actually works. just chucking a ball around, even if u hav no faith that it will work. it does. magically.
if you sit down and break up your mono into sections it's good too. paragraphs or ideas, and then highlight the bits you continue to forget. there are always bits you have no troubles remembering, then there r troublesome bits. highlight them, and you can sometimes begin to havea photographic memory of those particular bits.
remember, it is okay to pause in the monologue. if you forget a line, as someone has said already, just ACT like you haven't. people don't even notice if an actor repeats some lines by accident. just do some relaxation things before going on stage to focus your mind. it really helps. it can look a bit wanky but dont let it bother you. u will do a far better performance if u are focused and aware of yourself before u go on. no good going on cold- bigger riks of forgetting lines and getting really nervous.
do some deep breaths in, do a spinal roll (classic relaxtion tool!) or two, and do some mouth and voice wamr ups. mouth wwarm ups arent just voice warm ups either, they are two separate things.
good mouth and voice warm ups include doing some hard 'F,F,F' sounds, then some "S,S,S", then a big "SHHHHHHHHHH" horsey sounds (not a 'neigh' but that 'shhhh' sound they make where you let your lips loose so they can vibrate), where you loosen everything.
they are my faves.
just make sure u feel fully prepared, thats the best way to beat nerves.
break a leg.
