If you want to fight a parking ticket, then your fight needs to start immediately after receiving the ticket. You need to document what it is that you feel proves your innocence. This usually means taking clear photographs of the area. The ticket could be the result of a missing sign, a blocked sign or a sign that is covered by graffiti or stickers or some other type of cover. Or there could be chipped or faded paint that indicated a parking law which you where found in violation of. Additionally, the meter you were at could have been broken. Or the meter could be improperly calibrated and not kept up. If the proof of your innocence can be proven with a good picture, than take that picture. Also, carefully examine your ticket. Make sure all the details are correct, as a ticket with errors can be considered grounds for a dismissal.