1. Train yourself to ask the client about the project timetable. If they haven't one . . . well that tells you something about their organizational practices and attitude toward the project, doesn't it?
2. Add a "sell by" date to your quote (e.g., "This bid is valid until [a date six weeks from now, or six months, or whatever length of time makes you comfortable]).
*This sometimes spurs clients to act before the deadline has passed.
* It will protect you if a client should bring you a year-old proposal and want you to work at the same price no matter what.
* You can consider the bid rejected if you don't hear by that date.