If you don’t already do this, I highly recommend you begin.
If a client contacts you about a project and your schedule is already full, then take the initiative to tell the client what does work for you. Something like, “I’m afraid I’m not available at that time, but I can write the index if the due date can be extended by two weeks.”
I am often pleasantly surprised when the schedule proves more flexible than it initially appears. I would not have known unless I asked.
This tactic does not always work, of course. Sometimes schedules are firm and the client decides to find another indexer. But if I am interested in the project, it is always worth asking.
(Of course, some projects I am not interested in and am happy to let pass.)
It is important to remember that we, as freelancers, have agency. Simply responding to clients with a yes or no, without any further information, is letting the client control negotiations. So if a schedule or other detail does not work, make a counter-offer. Tell the client what does work. Give the client an opportunity to meet you partway. Now you are taking the initiative. The client has agency too and may reject your proposal, but at least you have spoken up for yourself and explored all options.
Similarly, if you see an upcoming gap in your schedule, contact past clients to see if they have any upcoming work. Let them know your availability. Assuming you’ve previously had a positive experience with the client and want to work with them again, contacting past clients can be one of the easiest ways to market yourself, because you already have an established rapport and track record. A short message puts you front of mind and may prompt them to take action if hiring an indexer has been on their to-do list.
Taking this a step further, schedule a regular, quarterly check-in with past clients. Say hi, let them know your upcoming availability and that you’d love to work with them on another project. Maybe include an article or other tidbit they may find interesting. Be a good and proactive partner, so that they don’t forget about you.
Being a freelancer can involve a lot of waiting for that next project and hoping that schedules align. But this waiting does not need to be passive. Remember that you have agency too. Make counter-offers. Proactively share when you are available. You may be surprised at what becomes possible.