Method #1
So, start by removing the drywall completely off your ceiling. If your drywall is in a decent condition, then keep it aside, as you can reuse it later. Also, reusing the same drywall will save you time in cutting new drywall to fit in your ceiling. So, strip off all the layers of your ceiling, till the wood struts can be seen. Then start applying a layer of foam. Use the most dense foam possible. Remember, more mass means better soundproofing. So, use good density foam layer.