You just need to practice. Roll a kneaded eraser over the art a lot. Graphite/lead fills the pours of the paper and the ink cannot soak in. The paper is a sponge. It just takes time. The kneaded eraser picks up the graphite/lead that is sitting on top of the paper. That lead (it's not really lead but i'm tired of writing it all out) is what smears because the lead can't stick to lead. It also prevents the ink from soaking in.