I pretty much agree with tazman. I usually leave my clothes hanging outside for a few weeks before season and then cut some of the leaves and twigs from the type of tree I will be setting in and put everything into a plastic bag. I also believe that fresh earth spray and raccoon urine work as good cover scents.
advice: you can safely spray fresh earth scent all over yourself and clothes, but I have found that spraying raccoon urine on anything but your boots can make you sick as hell. NASTY!