Yes, you’re here for marketing advice, and we are telling you to refer work out to others. You will get a client from time to time who you cannot help, whether due to time constraints, or because they require something outside your area of specialty. Rather than take on something for which you are not capable, or worse yet, turning them away with no help whatsoever, make it a point to refer this client to another.
This could come back to you tenfold. For one, you will have made a possible friend and ally in your area of business. They will remember your kindness and have a hard time saying no next time you need a favor. They may even return the favor when they get a client they cannot help. With some luck, you may generate a successful mutual referral system. Lastly, you will help yourself-you do not want to develop a reputation as someone who turns prospective clients away without help.