Preparation is Key
1. Let your cream cheese come to room temperature instead of using it out of the fridge - if it's too cold it will be too difficult to mix.
2. Use a waterbath
3. If you have one, use a springform pan instead of a standard one - it makes it much easier.
4. Before your add the eggs, mix the ingredients really well to make sure they are all combined and that there are no lumps.
5. Don't overmix after you've added the eggs though as these are what hold the air in the mixture, so mix them enough to incorporate them but then stop!