(a comatose, hungover sounding) "Hello?"
Not exactly the best first impression. So if you give bad phone (or aren't aware of your phone presence) you may be doing yourself a disservice without even knowing it. Here's what I'd suggest:
"Hi, this is (your name)"; or
This is a professional way of answering the phone. And for those who are worried about their friends making fun of them for the new way they answer the phone, you have call display anyway - so you don't even have to change the way you speak to your friends.
2. Smile when you answer the phone. You'd be amazed how smiling can affect your positive energy on the phone.
3. Breathe before you pick up. Get into a good headspace before you pick up, because you're going to have to get through more than just "Hi" if it's a recruiter.
4. Have a friend, or better yet, your parents, evaluate the way you answer the phone. Get their honest opinion of how you can improve.