Personally.. I believe that every weather starter should be running leftovers. In the Smogon Doubles Metagame it is hugely important to rule the weather to allow for your abusers to function properly and to effectively limit your opponents' weather abusers.
I am currently running sand on one account and rain on the other and I use Leftovers on both weather starters just to ensure that extra longevity and recover with protect when needed
Originally Posted by Fat HabibsHotDogs
There's quite a few viable leftovers holders, for example water absorb pokemon with surf teammates can viably last multiple turns in order to justify using leftovers, I'll be doing a feature piece on one of my favourite doubles pokemon that can do really well to support its team with leftovers shortly! Preparing it now.
I'd just like to say firstly that I haven't been using the Surf + Water Absorb strategy (at this stage anyway..) but personally I believe that perhaps Life Orb would be a more effective item choice. Why? Because you are already getting the recovery from your team mate in surf and this allows you to hit like a truck and effectively negate the LO recoil + receive some extra HP recovery. Or even Scarf Water Spout Jellicent could benefit from receiving the HP recovery to supercharge its Water Spouts. I can't really see any/many instances where Water Absorb + Leftovers will be favourable over LO/Scarf/Specs/Band etc