When we moved to this house it was the first time I didn't have a bathroom on the main floor, or each floor for that matter. We either have to go up stairs, or down, for a bathroom. We brush our teeth a few times a day, so my solution was to put our toothbrushes in the same drawer as our silverware. It's close to the sink where we can easily get to them, without having to go to another floor. When doing this, I decided instead of washing our toothbrushes periodically in the dishwasher, we now wash them each time they are used.
Of course this means we each have to have more than one toothbrush. We each have specific colors we use, or we write our name on them with a permanent marker. Mostly for my husband, he's the one that has a hard time remembering his color. Once a toothbrush has lived it's life, it gets a new use as a cleaning utensil. They are great to use to scrub in those hard to reach places!