While sometimes, or most of the time, cleaning your camera feels like a big hassle it is important and necessary. Tiny little specks of dust, grime, basically the environment can get stuck in cracks of your camera or onto your lens. It’s good to routinely clean your camera for your pictures to come out as sharp, crisp, and clean as you are wanting.
The biggest DON’T you will want to remember is the easiest, most available is not always the right choice. In this case, do not use the end of your t-shirt as a way to solve the problem of a speck on your lens. Your t-shirt most likely has grime and dirt embedded in it from your daily activities that would cause worse damage to your screen then simply leaving the speck there until you have the appropriate cleaning supplies, such as a microfiber cloth.
The easiest way to make sure the items you are using are appropriate for cleaning your camera is to buy a camera cleaning kit that would come with a variety of useful tools that would be more than sufficient in maintaining a pristine camera and lens. However if you would like to only buy the bare minimum a microfiber cloth and a cleaning solution. Also recommended would a brush with soft bristles such as camel hair, methyl alcohol, and an air blower. Please note that an air blower is not the same as the compressed air you use on your computer keyboard.
While you should clean your lens, as well as your camera often, it does not need to happen daily. Be aware of how long its been since you last cleaned it and plan accordingly. If it looks dirty, then by all means feel free to clean away. Some photo shoots are in places that have a less than ideal atmosphere for the cleanliness of your camera and would mean the a thorough cleaning would be in order.
Take care of your camera by cleaning it regularly and with caution.