Have you read about Tweening or Masking? Tweening
: When you do what I said, you can click a frame where you want the saber (or laser or wahtever) to start. Then where it ends and AlamDV2 fils in the frames for you automatically! The only problem with this is that lightsabers have a human movement to them, so youll have to be filling in a lot of the in between frames. For sabers I recommend going into alamdv 1 mode. This allows you to click the hilt and the top of the saber,and fit the saber perfectly to your toy saber. Then change back to DV2 mode when the saber is pretty still.Masking
: Say a lightsaber or any effect should go behind something, a person, a wall, anything. For this you will need to make a mask. Masks in AlamDV2 are in preset shapes. Say you want to have a lightsaber go behing someone. PLace the mask over the person where it goes behind them at the desired frames. For light effects, use a feathered mask, becuase this will result in a light spillage. For other effects, use a hard mask.
Watch some of Tarn's Tutorials
for more information