I know the feeling, the CTRL Death Grip :-) Do it enough and you get used to when things come undone. What kinds of things deselect, how to make the moves.
Of course SHIFT can be used. select the first Hold the shift, then select the last item, for selecting the whole row of something, then using CTRL to deselect the last few.
Inverse selection, select everything You do NOT want With CTRL, then use EDIT Inverse selection (normal menu).
Using Search instead, When fighting to select certian items, sometimes using search to find those items can be much faster than selecting. then the CTRL A can be used to select all of them. Searches can also be sorted, so a Shift select goes much faster. Learning a few wildcards then comes in handy. like
*(everyting and nothing) and ?(one joker) EX:
D*.mp3 all mp3s that start with D.
There is stickey keying (locking qualifyers) but that doesnt change the user making the minor errors and deselecting the bunch after having painfully selected.
Control Panel\All Control Panel Items\Ease of Access Center\Make the keyboard easier to use StickyKeys can lock the CTRL for you.
Split the folder up. just raw move half of the thing to better organised folder arrangements so there is not so many to have to deal with at a time.
Use a "side by Side" explorer windows, or different file manager, so you dont have to fight windows also. There are a few good 3rd party file managers that side by side the windows much better than piddling with windows doing that. Like Q-dir, I can have 4 folders open in the same one window. By doing that, I dont have to fight whole selections, the other folder is right there, I can move a few groups at a time.