Hiya
I'm at drama school too, and the way that works for me to get lines to stick is to record them on a dictaphone and just play it over and over, then test yourself as to what comes next, and also it's good if you can do a second recording of the other lines (ie with yours missing) so that you can then fill in the gaps. Works for me!
Hope this helps, good luck
When I was an actress (I gave up due to stress) I found that moving around the room with each new line helped me keep it in my memory. Most people learn the line for the sake of the line and then connect with the meaning afterwards, I found that if I learn the line with its objective and emotian it was easier to remember.
It does pose a bit of a problem if the director wants you to say the line with a differnt objective or emotion to what you have learned though.
Also put mental pictures with the line. eg 'Shall i compare thee to a summers day' picture a beautiful person and a sun,
'No, thou art more loveley and more temparate' move to the tv and picture something which reminds you of the word temporate." rough winds etc move position again.
It works. xx