Build forearm endurance.
Credit: Koji Ishibashi for Brooklyn Boulders

"The thing that shuts new clients down right away is a lack of forearm endurance," says Livesey. "For this, people need to just rack up a lot of mileage on the walls." Devote at least a few sessions to just climbing as many easy routes as possible (most likely V0s and V1s), with very little rest between problems – remember, you're building endurance, not strength at first. Once you can climb at a grade you're comfortable with, for a full hour without feeling that all-to-common forearm "pump," begin to incorporate harder routes into your workout.