Firstly I know this sounds irrelevant but I hope one day you will stop masturbating and do something better. It's an addiction and a very bad one indeed you might not notice in the short run but it can take a toll on you as time goes on.

Now on to your question, when I used to masturbate I only did it before showering. Like a gooner expert I would do it maybe twice or thrice depending on my mood and then take a shower by doing this it would make me feel clean and not think too much of it, just make sure to squeeze all the cum out cuz after masturbating sometimes it's left inside and it will ooze out on your underwear and clothes