I like to use my Dual Chop/Night Slash/Earthquake/Dragon Dance set, and merely support it with Volcarona, which is successful BOTH in sun and rain...

A short presentation with MY signature set:

Salamence @ Yache Berry/Leftovers

Ability: Intimidate (cannot have Moxie with this moveset)

200 Att, 110 DEF, 200 Speed, Jolly Nature

Moveset: Dragon Claw, Roost, Iron Defense, Dragon Dance

This is totally different than your normal set Salamence, and I've used it to suddenly wall otherwise offensive teams. Dragon Claw is there for STAB and attack when it sets up, or otherwise simply sweep. Roost is of course to recover damage it has absorbed while setting up. Iron Defense to wall physical opponents (ESPECIALLY Ice-types), thus making it potentially last longer. Dragon Dance to outspeed and outgun opponents.

As this pokemon CAN take time to set up, assistance is required, from rock, fire, electric, and other types to counter bulky waters, steels, and other such pokemon that are easily able to take this dragon on, even after setup. Special attackers are to be watched out for, as well as pokemon with Ice-type and other priority moves.

Status-inflictors are also a hazard, so be sure not to spend TOO much time in setting up in the event that a wall comes to greet you. (Trust me, I've suffered through parahax with this thing against a ferrothorn, and I HAD to set up eventually or die, and it was NOT fun.)

As for weather, be sure that it sits either in rain or sun, as Sand and Hail hurt it, and the object of this moveset is to keep Salamence alive for as long as possible, so the use of a Ninetales or a Politoed (or heck, even BOTH) is encouraged to throw off your opponent.

Similar sets may also be used with other pokemon, and it has been effective through testing.