Use Rotto air taxi, they are quite cheap and do a day rtn, save the hassle of flying yourself. You can walk from the terminal to the town and bike hire, otherwise there is a regular bus around the island just wait outside the terminal until it arrives.
If you do fly yourself don't worry to much about the crosswind unless you are in a tail wheel a/c, I flew the rotto air taxi for a while and its really not as bad as everyone around Jandakot tells you.