Switch boxes are generally placed to help the drywallers. You want the seam of 2 sheets of drywall to be on top or the bottom of the box and not in the middle of the box. That way only 1 sheet has to be cut for each box.
An upstairs room will have 5/8" drywall on the ceiling joists. The top wall sheet butts against the ceiling drywall and then the bottom wall sheet below that. Many like to leave a 1/4" or so gap at the bottom above the floor is possible. Measure 48 & 5/8" from the open ceiling joist. Having the box above or below the seam may depend upon your height and reach, etc. Above would be too high for me. It also allows making the cut on the bottom sheet where it is easy to stand up against the wall and make the cut.
In the basement with lower ceilings and the possibility of using a suspended ceiling or something other than a drywall ceiling, it will be different. With walls less than 8' high, you may want to run your drywall sheets vertically to avoid end butt joints.(its hard to get 12' long sheets in the basement) If run horizontal, you may have to do some lenghtwise cutting on one row of sheets and you would have to determine how and where the seam may be. The narrower sheet may be at the bottom or the top. At any rate, this rule of thumb for seams and boxes may not be that important in the basement and you can just put them at the same height as upstairs so they are uniform and what you are use to. It is kind of like stair tread heights, you get used to a certain height and one that isn't the same can cause a fall.