You are one of more than 500,000 apps on the App Store. Don't be a me too. Be unique. Offer up interesting information about your app and why the media should cover it. Remember, you're not the only one with the most useful or fun app in the world.
Don't wait to start your app PR strategy until your app is available. Once it's available, it's old news. App review sites have too many new and exciting apps to cover that waiting doesn't help. Think about starting outreach a month prior to launch. Create a dialogue.
App PR Tip #3
Be social. Facebook and Twitter will be two of your most successful promotion channels. Learn them, love them and live them. Invite your friends, family and strangers to be a part of your community. But remember, don't sell to them, get them involved.