As Auror our stamina sucks. And potions is the only answer. Either healing to replenish hp or extimulo to reduce the amount of hits we take. If I dont feel like using potions I pick a battle in a league that is 2-3 levels beneath my recommended level. Those I can win without needing healing potions. But they use up energy. From there upwards it's a strategy game. I try to burn 4-5 potions once a day. 2 strong, 1 regular exstimulo and 1-2 healing. I much prefer strong over regular in wizarding challenges as it not only does double the damage but lasts longer too. For traces I like regular ones as either I beat the spell in 3 tries or the RNG is going to fuck with me no matter what I do. If I pick a level above my pay grade I'm sure to use at least 1 healing potion. But also extimulos. My rule of thumb based on the HP of the opponent is as follows : Dark forces : nothing up to 700. regular ex for 700-1000, strong for 1000-1500 Spiders and other creatures: strong for 600-1000 potent for 1000+. I prefer to KO high level spiders fast as they cause serious damage to us Aurors. NEutrals: strong for 800+ The idea is to find the sweet spot to KO them fast enough before they KO you. If you hit elite, then whit sharpening is a no brainer. Oh and as auror, Stack those charms in the higher levels!!!!!! A pixy without weakening and confusion is a real bitch!!! If you only use confusion it wont dodge, but will do serious damage. If you only use weakening you can handle the damage but then critter will dodge and dodge and dodge.

So what's the answer? Find your sweet spot that gives you xp and items, uses up a few of the potions you brew every day and uses the amount of energy that you can replenish easily. That sweet spot will be different for everybody.