Here is a moveset that I thought up yesterday. I thought it was 100% original until I realized that it was a slight derivative of a great moveset that Bliksem posted in the Jolteon thread that I created.
Anyway, here is's Bliksem's original moveset.
Yawn
Substitute
Thunderbolt
Baton pass
The point of this moveset is that it is pretty much a win-win situation once you get the yawn off. If the opponent doesn't switch out after next turn, they fall asleep and are bait for whatever you decide to switch in. If they switch, you get a free sub on the switch. If they choose to attack you, they destroy your sub, and now you can lay up another one as they now have to either switch out and leave your sub up, or stay in and fall asleep. You can also pass the sub off to another teammate.
Here is where the moveset changes a bit.
Jolteon Petaya Berry/Expert Belt
Yawn
Substitute
HP Ice
Thunderbolt
Yep, this Jolteon doesn't pass substitutes, but it can hold off the fort on it's own a little bit better. This is where the prediction games come into play. Switch this jolteon in on something that you know can't hurt you (like a flying type or another electric not named Electivire, Raichu, or Lanturn) or after losing a previous pokemon.
Now you try to predict what the opponent will do. Will they switch or not? If you think they will switch, use yawn then substitute. If you think they will stay in, use the move according to the situation. For example, if you have Jolteon in on a flying type, chances are that they will switch that flyer to a ground or grass type right? Use hp ice to nail them on the switch. Even if they don't switch, so what? HP ice will still do a lot of damage to the flying type, and they can't hurt you too badly. Besides, why would a flying type (unless it's Gligar's evo or Aerodactyl) want to stay in on an electric type that has 130 base speed, 110 special attack, and a stabbed thunderbolt? That would be suicide. Hp ice also helps if they are trying to use the flying type bait to speed up Electivire. If you know they won't switch, then tbolt to death.