In one sentence, describe what the following article is about:

When you arrive to the elevator, decide which way you are going and be ready to wait. An elevator's arrival time can be affected by many factors such as elevators' traffic, the amount of floors, rush hours, and available elevators due to unforeseen maintenance or closures. Stand clear of the door. This etiquette is practiced in a lot of public situations such as subways or buses, and elevators are no different. Also, keep in mind elevators serve individuals who suffer handicaps or people handling large loads of cargo or furniture. Take a step aside and allow passengers enough space to make their way out of the elevator. Take a second to ensure that the elevator car stops at your floor. Most elevators have signals to show if they are going down or up. In the case where you cannot find any signal, ask the passengers on the elevator which way they are headed. Avoiding going in the wrong the direction, especially if the building has a lot of floors. When the elevator stops at your floor, it might not mean people will exit. If the doors open and passengers do not get out, assess what space remains. If you cannot see enough room for you, let the doors close and wait for another elevator. Elevators vary in size and available space. Locate a section where you will feel both comfort for the ride and convenience for your exit. The back of the elevator is the ideal location two-fold:  it leaves room for other passengers to enter or exit, and it secures a good spot for longer rides. Elevators have buttons on either sides of the door. The majority of the floor buttons are numbered; basement, garage, street level, lobby, etc. may be represented by letters.  If someone is standing closer to the buttons than you, they might offer to select for you. If they do not, kindly ask them to select the floor. In some elevators, double-tapping on a lighted button allows you to cancel a floor call

Summary:
Press the "up" or "down" button. Allow any people to leave before entering. Make certain the elevator is going in your direction. Decide if the elevator has enough space. Enter and find an empty spot in the elevator. Select your floor.