I belong to a twink guild that runs 10v10 premades in multiple brackets (Mostly 29 & 39, but we dabble in 19 & 49) against other top notch twink guilds on a regular basis. Because of this, we always need the top consumables to compete with other twinks who are equally geared to the teeth.
While we can make most of our consumables, some are harder to come by, like scrolls. I figured out the best way to farm them though: Thaddeus Paleo Aka "The Professor" Outside thunderbluff at the Darkmoon Fair.
Every time the Darkmoon Fair is around, park a toon right on top of The Professor, and periodically log on throughout the day to buy all the scrolls and potions. The respawn rate on these is absurdly amazing! Rinse and repeat every time the carnival comes around. If you have 2-3 ppl from your guild camping this guy, you'll be set for a long long time.
If you have any questions about twinking from 19-49 I know about every class except for warriors in every bracket. Send me a PM or something.
Edit: I need to l2tipegud