its very important that you dont "naturally" transition into the drama/grudge filled stage where u feel like you have to be mean to each other n start goin out of your way to make the other jealous and angry.
there is no use in playing the polar opposite of the same thing, just move on the thing as a whole as if he doesnt exist.
Once everything is finalized quit thinking about him, quit answerin his calls, and ignore any attempts to get on your bad side.
like others said, it only gets better from here so make sure a *real* moving on happens.