The best way to get property rented as soon as possible is to advertise it on property rental sites, like https://rentberry.com/ and http://www.zillow.com/. The second one has syndication feature, that share your listing to other property rental sites.
But don’t forget that still many people look for rental properties in the newspaper. So, post the vacancy there too. The social media, such as Facebook and Twitter could be helpful as well.