It is good practice to post your Sailing Trips at least a week in advance, giving people plenty of time to join and plan for the sail.
If you are going out sailing on the week-end, make sure you post your trip by Monday or Tuesday at the latest, so that it can be featured in the sailing trip summary we send out every Wednesday to the entire community.
Once you have posted a few sails, and built your network of Sailing Buddies on GoSailing you will find it easier to get crew even a few days before your trip.