We appreciate clients and projects that want to engage in a real collaborative exchange with us, rather than looking for someone who can make their ideas look nice.
I can really understand, but given my schedule it might be quicker and more convenient to do this over the phone or email.
I know this project is a high priority for you, and if it’s absolutely necessary for me to turn something in by that date, I can make it happen. But if I could have a few more (days, weeks, etc.), I could really deliver something of higher quality. Would it be possible for me to have a bit more time?
I appreciate you thinking of me, and I’m honored by the request. But unfortunately, I don’t have the time to give this my best right now. I think you would benefit from finding someone who can devote more time and energy to this project.
I would love to help you out, but I already made commitments to other clients to complete their projects today. It wouldn’t be fair to them to not follow through on what I said I would do. I will be sure to fit this in as soon as possible. Thanks for your understanding.
I would love to help you out, but given my schedule, I wouldn't be able to get this back to you for a couple of weeks. If you would like to have this turned around sooner, I recommend that you reach out to XYZ. Does that sound good?
I would love to help you out, but I already made commitments to other [coworkers, clients, etc.] to complete their projects today. It wouldn't be fair to them to not follow through on what I said I would do. I will be sure to fit this in as soon as possible. Thanks for your understanding.