If you're using candles and incense, then burn them until they're completely out. But if you have excess herbs and other things like that, you can either bury them or throw them in the wind. It's up to you!
Re: after the cast By: kts Moderator / Adept Jun 25, 2015
Post # 4
Used items from a magical casting can be handled in several ways. Once may bury the items in the earth or burn them in a fire. Some may choose to scatted the ashes or other items to the wind. If doing any of these be sure to remove non-biodegradable parts such as the metal from a wick or the metal holder of a tea light. One can also opt to simply throw the items in the trash. In the end it will be buried or burned. Sometimes the items from one casting are reused in another working. I have often used pieces of wax from one working for another. Such as a poppet. I often use the left over wax from candle burnt for a specific person to fill a poppet of the same person.