Level Mate Pro

Best addition I ever made. Mines going on 5 yrs now. Get the Andersen style levelers (the curved triangle ones) to go with. Pull into your spot. From the driver seat fire up the app and see which side is low. Have your helper put in the blocks, pull forward until the app says you're level (side-to-side). Set the brake, get out, unhitch, and then watch the app as you raise/lower the trailer to front/back level. Done.
With the Andersen style, it is only a really unlevel site where I have to break out the legos, and even then the app tells you what height you need to build them to.