[He leans on the side of a counter, mopping at his brow again as his general irritability takes a backseat to his weariness.]

Most of the ones I could make quickly and easily are superficial. Cheering and relaxation, things you'd think might be useful, also can make your mental processes less than perfect. Bad idea, for potionmaking. The famous ones that do wonderful work are dreadfully complicated. Side-effects as well.