Blocks under the tire can be a pain in the neck if you don't get the right height - back up, add another layer, try again. That's my opinion after camping with a camper van anyway.
A couple of ideas to make leveling the trailer a little less onerous:
- Get some pieces of wood (or a set of those plastic leveling blocks) to put under the jack(s) - a lot less cranking required. We've got five or six 8x8 blocks (cut up 2x8 pine board) - they fit in the outside storage compartment. Wood is nice because you don't cry so much if you leave them at a campsite (ask me how I know).
- We keep a little leveling bubble that we put on the counter during leveling but if you're by yourself, you could stick one on the tongue plus one on each of the flat spots on the bumper frame (if you have one) so you can watch the level as you work.
- Maybe consider switching out the crank handle for a ratcheting wrench? I've also seen guys bust out a corded drill at some (electric) campsites.
- Keep the jack well lubed - it gets pretty dirty down there!