1. Donate anything covered in dust. If it's been that long since you used it, do you really need it? It's likely you haven't been enjoying it if it's been long enough to catch a coating of dust. Someone else is probably looking for that exact pressure cooker/fondue pot/Cookie Monster cookie jar. Let them have it, because you're not using it.
2. Trash anything broken. If you don't know how to fix it or it's more expensive to fix it than to buy again, don't waste your time. I realize we live in a society that relishes in disposable products, and I'm all for trying to save and reuse what we can. But, take a realistic deep breath and ask yourself if you're making life easier by hanging on to this project.
3. Recycle all the random lids for which you can't find matching bottoms. I don't think we need to talk more about that. Do you?
4. If the food has changed color or smell, toss it. If you want to go by 'Sell By' or 'Use By' dates, please do. If you'd rather go by your senses, trust your sight and smell. Jarred things that have separated, spices that aren't the right color and liquids that have a layer settled on the bottom can all get emptied in the trash or disposal.
5. Wipe it all down. You'd be amazed by how much different a space can feel just with the wipe of a rag. A quick wipe of cabinet shelves and drawer bottoms will add an instant, quick lift to your entire kitchen. Don't forget the inside of any bin or container, too. Stop that mystery goo in it's tracks!