Team up with an agency or group of other freelancers. Then you can specialize and do what you do best(coding or design, for example). That way a higher percentage of your hours will be billed, you'll have less stress, work will be better, client will be happier and pay more, and you'll never leave a client on a limb if something comes up because there will be a team to pick up the slack. Source: did freelancing part time for 5 years and worked with 2 agencies for 2 yrs. latter was 10x better