What is often an inconvenience to you during a 24 hour period? Is there something you have to look for or clean or unbury? Is there something you trip over or grope for? Is there something you have to do to make yourself more comfortable at your desk or table or computer or bathroom sink or bathtub or shower or at the wheel of your car? Find one of those things and arrange the environment so that inconvenience is taken care of in advance. Then, when you do the ordinary, an ordinary courtesy makes that ordinary action more pleasant. That's the power of courtesy.