Counting your breaths may help – count each breath and when you reach ten, start over. However, if you become focused on the numbers and not on the breathing, stop.
Another alternative is repeating a mantra – there’s a reason some people say “Om” when they meditate – it helps drown the outside world and focus on the sound. You can repeat any other word that helps you calm down if Om is not for you.
Try visualizing a calm place – it can be anything: the beach, a forest, your childhood home, etc. as long as it’s your sanctuary. When you find your sanctuary, don’t be afraid to explore it – there's no need to try and “create” your surroundings, they’re already there.