The above advice is spot on, in about 90% of the guns out there.
Once you get used to it you should be able to pull the front trigger and instead of letting go of it with your finger and re-inserting the finger back into the trigger guard onto the rear trigger, just slide it off the front one smoothly back onto the rear one. Handy for quick doubles, such as doubles on skeet station 7, or simo pairs in sporting clays. That's why the front trigger is often given a soft radius along the length of its right side, to allow the trigger finger to easily slide off and back.
Yeah - you don't want to double finger those triggers, or the recoil for the first will set off the second. Hard on the shoulder, but pretty deadly.
Don't ask how I know....
Factories back in the day would special order odd ball choke arrangements in doubles. Ie: the right barrel being the tight one. (Not to mention the abundance of choke reamers out there, and guys who know how to use them.) So don't automatically assume the right barrel is open and the left tight- the pattern board is your friend when you buy a new gun. More than a few discerning guys wanted them choked that way. (Admittedly that is rarely to be found in hardware store-grade guns though.) Then there were the guns that were choked identically in both barrels- usually guns meant for waterfowling and choked full and full, or open-and-open for close quarter bird shooting. The "name" factories would also special order (at no small expense) triggers set up for left handed shooters, with god knows what choke combinations.
