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Let's Play Dust: An Elysian Tail Part 5½: Quick Level Grinding
I found a good spot to grind out a level every five minutes or so. Right before the midpoint of the Sorrowing Meadow, there is a cave with a beehive both outside and just inside on the next screen. Just go back and forth slaying bees and zombies with Fidget's lightning and Dust Storm. The hives are worth over 1000 experience each, you'll get hefty experience bonuses from the large combos you rack up as you destroy them, and through both of those you'll very quickly gain levels.
Equipping a Ring of the Apprentice or Master Ring of the Artisan (or two) beforehand will further increase your gains.*
*The blueprints for these items (and indeed, nearly all items) don't seem to drop from any specific enemy; rather, they just seem to be based on your current level and/or your Luck stat. I eventually got blueprints for both of these and numerous other pieces of equipment just by killing a lot of bees and zombies...