This is pretty much just switching a tune! If you want your mix or set to sound as good and creative as possible then you must vary as much as possible what you do with your tunes.
JUST A FEW EXAMPLES:
-Double dropping
-Starting a new tune as soon as the previous one drops and mixing it from that point onwards (usually better with progressive tunes without a drop)
-Switching the tune
-Mixing a tune and switching it at the drop
-Slapping in a new bassline to the tune thats already playing
In my opinion the more you can vary between these sort of things the more exciting a set will be becuase if you just double drop for example (not to say thats shit) the mix will be soooo predictable and who can say they dont feed up when an unexpected bassline comes into an already rolling tune!!