No matter which type of toothbrush you use, keep it clean. The American Dental Association suggest to rinse the toothbrush thoroughly after each use to remove any remaining paste and debris. Store toothbrushes in an upright position after use and allow them to air dry. Storing a moist toothbrush in a closed container promotes microbial growth more so than leaving it exposed to the open air.
Storing a toothbrush in a closed container can cause bacteria to build up, so it's best to let the bristles of the toothbrush fully dry between each usage. If you're travelling, consider using disposable toothbrushes during the trip.
How often should you change your toothbrush? Get into the habit of buying new toothbrushes for everyone in the family several times per year. How often you change your toothbrush depends on several factors, but it's best to always have a new, fresh toothbrush waiting in the bathroom cabinet for each family member.