Tall individuals
If you are a tall person, you may find that standard desk heights feel cramped and force you into an unnatural and overly hunched position. If that is the case, a height-adjustable desk will present you with a better set-up to accommodate longer legs and arms.
The overarching advice, however, does not change, which is to have your feet flat on the ground, with knees at a 90-degree angle to prevent any discomfort.
Shorter individuals
Shorter individuals are more likely to experience discomfort with desks that are too high for them, as it leads to raised shoulders and/or strained wrists.
The advice is similar to that for taller individuals: a height-adjustable desk set to a lower position will be most beneficial.
It may also be worth considering investing in a footrest, as this provides additional support by ensuring your feet are planted firmly on the ground.