Do your research. Write out a list of questions about the tasks, the amount of work expected, and the area around the farm. Will you be mixing concrete or picking the late harvest from the vegetable garden? How many hours will you be working? Do not commit until there is a clear idea on both sides as to exactly what you will be doing. Make a phone call, if necessary to clarify these issue and to have a good conversation before you book your stay.
Find out if you will be working alone. In our experience, WWOOFing is always best when shared with friends. Hard jobs become much easier if there is someone to share them with.
Keep an open mind about the tasks that come your way. It is all-too-easy for first-time WWOOFers to assume that they will learn far more about organic agriculture than is actually the case. Often, what is required is little more than manual labor.
Be prepared to entertain yourself. WWOOF hosts tend to be busy people, so do not assume they will have time to show you around the area. You are also likely to be in the countryside, so do not expect trendy cafes and tourist attractions on your doorstep.
Do not commit for a long time. Start with a few days and extend your stay if both you and the host are happy. Better that way than arriving somewhere and feeling you have to stay, even though you are not enjoying yourself.
Be respectful. Remember that you are going into someone's home. A good host will make you feel part of the family. In exchange you can keep relations smooth by cleaning up after yourself and politely asking before using anything.