Referrals convert better than almost any other lead source, because the trust transfer from a happy past client is worth more than any amount of advertising. The mistake most remodelers make is treating referrals as something that happens passively, rather than something with an actual system behind it.
A simple structure that works: a small, genuine thank-you (a gift card, a discount on future work) for any referral that turns into a booked job, asked for explicitly at the moment a client is happiest - right after a successful project wraps, not months later in a generic email blast.