Memorization of Lines:
I like to break it down by scenes -- and use my blocking and props as cues. For example, when I was Ethel in On Golden Pond in the opening scene when they arrive at the cottage and start taking off the dust covers, rolling out the rug, etc., she's talking the whole time -- so I'd walk it through, thinking she says X when she gets by the fire place, she says X when she's shaking out the pillows at the sofa, she says X when she grabs the rug and rolls out it, etc..
To sit there looking at a book of lines and just reading them over and over is overwhelming to me, but when I get up and walk it through and put it in the context of the scene with the blocking, the character, and the interaction with the other characters and props, the lines come much easier to me.