Some nights if I've sat on a spot for 2-3 hours and not had many bites I have found it productive to pull up the anchors and very slowly move around a bit. Bump the trolling motor just enough to put a little angle (<45 degrees) on your lines going down into the water and then let off. Allow the boat to stop and the lines to settle back to a 'straight down' position. Sit there a few minutes and then bump the trolling motor again. This little bit of movement is often enough to trigger strikes. Again, the important word here is SLOW!!!! Move slow enough that you're not running away from all the bait fish you have attracted with your lights. Also, this doesn't work very well if there is much of a breeze, which there usually isn't at night.
Follow Me, and I will make you fishers of men...Matt 4:19