Tip: Don't use your cellphone while driving. It's not worth it, and it can wait.
If you must use your phone while you are behind the wheel, have a hands free option such as a Bluetooth earpiece. If you require directions--set your map ahead of time. Most smartphones come equipped with a voice system that will vocalize the directions for you while your phone is connected. There are also several apps, if it is not a standard feature with your phone. Utilize this technology! You can connect with Bluetooth, auxiliary, USB, or even the lighter plugins that are specific your device.
If you're concerned about music that is connected via your phone. I recommend creating a playlist ahead of time. With some of the newer technology being embedded into cars, you should be able to skip a song right on your dash with the double arrows/forward button. If your car does not have this, try creating that playlist as an alternative.
Text messages can wait. Unless your car has a voice command where it is capable of reading/responding to your messages. If you need to, have a passenger help you with what you need on your phone.
Most importantly, if you know something on your phone desperately requires your attention: pull over. It's not worth the risk.