When you would honor the Divine with a gift of thanks or prayer, you can bring them to the Altar as an offering.
Often flowers are kept on the altar as an offering. Anything that is beautiful or special to you, or symbolic of the purpose for the offering, can be offered.
Placing your offering in an offering bowl is both practical and aids in keeping the offering special and setting your intent.
Offerings are one of the most overlooked practices, yet one of increasing spiritual power and importance.