Kat has good skills with low cooldowns its good to start off with Shunpo to get away form enemy champions or finish them off after your teammates have hurt them you could switch up to bouncing blade if you would rather farm first instead or attack killer instincts i only use for the passive unless you feel like you need to farm more try using it with bouncing blade to help move the farming along the ult is great does massive damage and lets you know when its definitely gonna hit this should be in those moments with multiple enemies it does great damage leading to multiple kills at once

i dont really mind much for runes just nothing dealing with mana regeneration because SHE HAS NONE

For masteries basically go for offense kat can be unstoppable once fed better to help move that along