Forum:How can I get better at Black Ops 2 Zombies?

HI, I am a player who has really enjoyed zombies in Black Ops and World at War, with my record at 64 on KIno der Toten. But I just can't do well on Black Ops 2. I mean, on easy I have made it to round 30, but on original even with others my record is only 19, any suggestions?