It really can be as simple as that as you go at your first drawer, then the closet, then the garage, then the basement...
Keeping only what you truly need and love in the kitchen is a great place to start. There are no doubt some relics in yours like that awful mug a co-worker gave you or the mis-matched dishes set that is all chipped. Unless you use these things often, you really don't need them and you can't tell me you love them. Take cue from this perfectly organized kitchen cupboard that seems to have everything you would really need - just the right amount of glasses, dishes, mixing bowls and prep bowls. Why have more?
Your clothing cupboard can no doubt use an overhaul too. This cupboard shows a very minimalist wardrobe, but I bet if you took everything out of your closet and only put back what you wear regularly, yours would look like this too. If not, it's time to re-think the amount of black pants you have, or how many sweaters you need in the same colour. Choose the ones that make you feel best when you wear them, and only those. Getting dressed in the morning will be so simple once you only have stuff you really truly love.
To summarize simply - Only keep what you need. Your life will truly feel richer.