This one might seem obvious, but many clients are hesitant to give real deadlines. I’ve had clients who say that there is no hurry, or to take my time and make sure the quality is excellent. While it is good to know when the client values quality over speed, it is still important to have a firm deadline when taking on new writing.
If you don’t ask about the deadline up front, you’re just asking for trouble. When the client says that there is no hurry, they may be thinking that it will be done in a week or less. When you hear that there is no hurry, you may put that project on the back burner for ten days or so while you finish up another project you have. Even if the client doesn’t say anything about it, they may be upset and start looking for another writer.
Asking for a firm deadline can help to avoid any miscommunications, and keep both you and the clients happy. Try saying something like, “While I’ll get it to you as soon as possible, I’d like to have a date by which you absolutely need this done.” This way they can give you their idea of the longest it should take, and you can plan your writing schedule from there.