What is your favorite mana drink of choice? I've seen a lot of people chug Kungaloosh or Honeymint Tea, and the potent Black Jelly is always superb, albeit a little pricey. And of course, if you have a mage in your group, you would be foolish to pass up some delicious Mana Strudel!
Personally, I love carrying enough food on me that I can sneak a quick few gulps for some quick mana regen between pulls, while a tank is waiting for a patrol to pass by, etc. However, my drink of choice is not any of the ones listed above, but...fish!
Not fish feasts, of course. That would be insanely expensive! Quite the opposite - there are a handful of fishy dishes that are often overlooked, despite usually being extremely inexpensive. Added bonus - they're just as effective as Mana Strudels! :O (Sorry mages!)
These foods are:
(cooked from Rockfin Grouper)
(cooked from Barrelhead Goby)
(cooked from Bonescale Snapper)
These "garbage" fish are commonly fished up EVERYWHERE in Northrend, usually when people are trying to catch other, more valuable fish. The Rockfin and Goby aren't used for any of the special buff foods, and while the Bonescale Snapper can be turned into Snapper Extreme (thanks to Shintar for pointing this out!), it takes THREE Snappers and a Northern Spice, so many players don't bother.
All three of these fish can often be found on the Auction House for extremely low prices, often a few silver each, but sometimes as low as coppers! I make a habit of checking every now and then and stocking up on the raw fish, and then mass-cook myself a few hundred at a time to ensure that I always have "throwaway" regen food handy.
That being said, cost is not the real benefit of using fish as trash food. Kungaloosh recovers just as much mana (though not health, only mana) and only costs 10s 56c apiece at Exalted with Kirin Tor to create, by purchasing Tundra Berries and Savory Snowplums. So even if you find a stack of Rockfin Grouper for 1c, you're only saving about 2 gold - which for most people at endgame, is pocket change. Still, when you're only drinking for a few seconds, the cheaper the food used, the better.
The real, subtle advantage of snacking on fish is that you can eat them at level 70! Kungaloosh, Honeymint Tea, Black Jelly...those all require level 75, and Mana Strudels aren't available until level 80! The level 70 vendor drinks, Fresh Apple Juice and the vile-sounding Pungent Seal Whey, only recover 12840 mana - vastly inferior to the 19200 mana you get from fish!
Now granted, the cooked "buff" foods are also available at level 70, and some do recover as much health/mana as the fish foods. However, downing a Spicy Blue Nettlefish or Imperial Manta Steak is a waste of resources and money if you're just sneaking a few swigs between pulls or topping off your mana. Buff foods and their raw ingredients usually sell very well - sell them, or save them for when you actually need their buffs!
Inexpensive, plentiful, and during those early Northrend levels, highly superior to their peers, FISH is clearly the food of champions! So save those "trash" catches when you're trying to get that damn turtle mount, and look for bargain fish deals on the auction house. You'll never be lacking for food again!
And no, I have no idea how you "drink" fish.