Don't Miss the Secret Moon Stones: Full Pokémon Firered Mt. Moon Map Guide
Can I return to Mt. Moon if I miss an item?
Yes, but not immediately after leaving. The eastern exit drops you down ledges on Route 4 that cannot be jumped over from the ground. You must progress through Cerulean City, Vermilion City, and obtain HM02 Fly (or loop back around through Vermilion and Diglett's Cave back to Pewter City) to re-enter Mt. Moon.
Which starter makes Mt. Moon the easiest to navigate?
Bulbasaur trivializes the entire mountain. Grass and Poison typing grants natural immunity to enemy poison attacks, while Vine Whip eliminates the abundant wild Geodude and cleans up Super Nerd Miguel's roster without difficulty. Charmander struggles most due to rock resistance and low early defensive stats.
What is the fastest way to catch Clefairy on 1F?
Keep a Level 8 Pokémon at the head of your party and activate a standard Repel. Because Clefairy spawns at levels 8 through 10 while common Zubat can spawn as low as Level 6, the Repel filters out the lowest-level common encounters, slightly raising the frequency of seeing Clefairy relative to wasted steps.