Evolve Eevee in the morning with high friendship. Try using the soothe bell. it makes a Pokemon really friendly in a short time.
Level 28.
The last person said to give eevee a water stone and DO NOT! That makes it a vaporeon. I don't know how but i do know its not a water stone
You have to get an Eevee and evolve it with full friendship during the day. Try giving Eevee the item Soothe Bell, it makes the Pokemon become friendlier way faster.
Only three (3) Pokemon evolve when the Thunderstone is used on them: Pikachu, Eevee, and Eelektrik.
You can't make eevee evolve into espeon by leveling it up. You have to give it a certain stone. I think it might be a moonstone, but maybe that makes eevee evolve into umbreon.
Evee can evolve by using a water stone to evolve into vaporeon, using a thunderstone makes it a jolteon, using a fire stone makes it a flareon. Now you can get espeon and umbreon in the game but its completely random. Just have the evee love you and level it up and it will evolve to espeon or umbreon and like i said its random. If you want espeon and umbreon the easiest way is to get them from ruby or sapphire or emerald or even Pokemon colosseum or even Pokemon xd gale of darkness.In Pokémon FireRed, Eevee can evolve at any level because Eevee can evolve into only 1 of 3 Pokémon in Pokémon FireRed. Eevee can evolve into a Vaporeon if you use a Water Stone on it, if you use a Thunderstone on it then it'll evolve into a Jolteon and if you use a Fire Stone on it then it'll evolve into a Flareon.
Train it at night time.
Nothing. You need to make Golbat to have Friendship or Happiness.
the stone close to the snowpoint city
a water stone makes certain Pokemon evolve like these: eevee-vaporeon staryu-starmie shellder-cloyster lombre-ludicolo panpour-simipour poliwhirl-poliwrath
Gible evolves into Gabite at level 24 and Gabite evolves into Garchomp at level 48. No stones just level.