Recently, I've had some move-up and move-out clients dealing with the selling/buying "chicken or the egg" quandary. Do I find a place before selling... do I sell first... do I try to do both and manage to time everything perfectly?
Everyone wants a deal... but the true way to get a deal on a home you really want is to sell your current home first, plan ahead for temporary housing then search/pounce on a real deal with the most aggressive offer.
The above assumes two things: 1. You own a home and, 2. You can't buy another home until you sell you're current home. You'll reduce stress, find the best home you can afford and be able to make the strongest offer with fewer contingencies.
If you're a renter, you may better shape... until that lease starts closing in. In this case, you might discuss your options with your landlord ahead of time. He/she may let you out of the lease early if it's a good month to rent out the unit. Or, at the very least, you may arrange to sub-let the unit. Whatever you do, plan ahead and take a little hit on rent if you have to. You do not want to pass up the home you really want in this market because of a few months rent. In most cases, some rent consideration can be worked out in the negotiation.
An example... say my wife and I reverse gears and kiss-off Chicago to move to the burbs. We'd move the family in with her parents in Lemont, prepare our current home show it's best, sell it, then look for the house we want. We'd be able really look and jump on the best deal with a no strings attached offer. Even finding a cheap temporary rental is better than trying to sell and buy all at once in most cases.