How do you guys pay for your game time.?

Have you got a secret to making enough isk to pay for plex.?

Started playing again recently and looking at the possibility of maybe multiboxing again, But want to have a plan this time before I jump into it again.
I recently took up PI after resubbing as a lazy way of making isk, got 5 planet setup and making goods just waiting to see how much I can make the lazy way.
So anyone got any tips on how to make isk to get plex to pay for subs.