Picking up consistently perfect fans has a lot to do with your tweezer hold. This was something that was never taught to me as a beginner and I have never this seen taught in a class, so I figured this out myself. I think it's one of the reasons why I never get hand fatigue and why I can consistently pick up fans.
I teach this not only to my beginners, but to volume students too, because I see it to be one of the major reasons techs struggle.
The aim is to have our grip low, this is where the control is, where the squeeze needs to be. By having two, but at best three fingers on our tweezers we engage more tendons, have a stronger grip, and have more control and prevent tweezer slide or twist ( ever find your bases cross - this is likely the reason )
If you " pen hold" the incorrect hold then your thumb does ALL the work, your grip is half way up the tweezers and your thumb pushes and twists the tweezers.
Ok there are techs that can pick up fans like this, but I consistently see techs can work improve when they adopt this technique. I have a fab video on my YouTube channel which covers this ( YouTube / Frankie Widdows eyelash excellence) and I will be speaking on this and other aspects of fan perfection in Hollywood next month.