The first thing you should do is check all of the common things that would make a baby cry. You should also be familiar with dunstan baby language to help you meet the needs of your baby. After you have checked the diaper, hunger, sleepiness, burp needs, and the general comfort of your baby then you may try some or all of my tips to quiet a crying baby. Keep in mind, I am not an expert, I am a new dad, but in this brief time of being a dad, I have developed some decent tricks.
1. Dance and sing with baby. Throw some music on the radio, something like stevie nicks or sarah blasko, something you can sing along to. Then hold your baby and dance with her. I often find this to be a good way to entertain my baby.
2. Make novel sounds that your baby has never heard before. Helicopter or space sounds make my baby happy.
3. Wear your baby in a sling…make sure it is not a baby bjorn as this applies too much pressure to babies pelvic muscles. I find that putting my baby in a kangaroo position in a ring sling quiets and puts my baby to sleep.
4. Watch Happiest Baby on the Block and use the techniques from this. For example, swaddle your baby, make loud shhh sounds in their ear, and gently jiggle them.
5. Have skin-to-skin contact with baby. Take off your shirt and babies shirt and let them lay on your chest next to your heart.
6. If all else fails, hand baby back to mom.