Sellers Won't Look At Your Offer IF....

If you have a house to sell, sell it before selecting a house to buy!
I know right now this contingence will put sellers off. This will work if your home has been on the market for some time and you have lowered the price to sell it fast because sellers do not want to be tied to your sale. Unless you are buying a new home in which case the builder has other houses to sell and can afford to put one on a contingency.

Let's pretend that we go out looking for the perfect house for you. We find it and you love it! Now you have to go make an offer to the seller. You want the seller to reduce the price and wait until you sell your house. The sellers figure that’s a risky deal for them, so they will pass you up for a buyer who DOESN'T have to sell a house.
Or he says OK, he'll do the contingency but it has to be a full price offer! You see, you could pay more for the house than you would have because of the contingency. Now you have to sell your existing house, and in a hurry! Otherwise you lose the dream house! So to sell quickly you might take an offer that's lower than if you had more time. The bottom line is that buying before selling might cost you TENS OF THOUSANDS of dollars. I always recommend that you sell first, then buy. If you're concerned that there is not a house on the market for you, then go on a window-shopping trip. You can identify possible houses and locations without falling in love with a specific house. If you feel confident after that then put your house on the market.
Another tactic is to make the sale of your home "subject to seller finding suitable housing". Adding this phrase to the listing means that WHEN YOU DO FIND A BUYER, you will have some time to find the new place. If you don't find anything to your liking, you don't have to sell your present home.