I often like to make a less traditional lasagna and have found that chicken and mushrooms make a simple, delicious combination. The DH and I love spicy so I really crank up the heat by adding a bunch of crushed red pepper but this is not necessary for 'normal' people. Once in a while I like to add spinach to this. You could probably add just about anything and it would be good. Using low-fat ingredients doesn't seem to change the outcome. I don't usually measure the cheeses. I use what "looks" right.