If it's a seller's market
In a seller's market, you may want to consider putting a property under-agreement that you want to buy first, as you could assume that your current property will sell quite quickly.
In an ideal situation, you could find a property where the seller also wants a closing a few months away, which would give you sufficient time to list and sell your property.
You may also want to only consider stating in your marketing/advertising that buyers must agree that their purchase will be contingent on you finding suitable housing. This can limit your buyer pool, but if the market is competitive enough, buyers may seek to be flexible with closing dates to appease you.