Something I do, When using a few objects very frequently, say 1 set of spikes and the blocks, I take those specific ones out of their sub category folder and drop them to the top of the objects left above all the folders.
that way I can access them efficiently.
then when done with them just put them back.
try also to think about where you might want some extra of the same object in advance, its easier to delete ones placed that you don't need after all than it is to switch back to fix the gaps.
that second tip isn't so easy to take advantage of though, so I don't really do it that often.