I either mix frozen (thawed, squeezed) spinach with ricotta, parmesan, a raw egg, and spices (basil, oregano) and then layer that with no-boil noodles and sauce, or if I have 3 hours to sit at home, I made this, which I absolutely love:
http://www.raisehealthyeaters.com/2010/04/family-dinners-slow-cooker-veggie-lasagna/
(it's easy- but you have to make sure it doesn't burn- so it's not a cook-all-day in the crockpot kind of meal. After 3 hours on the button in my slow cooker, it's perfect.)