We wait for the weekend, then throw the windows open, turn on some music and start from the top down. First a deep dusting using clean dust cloths and no product (maybe water if we need to scrub a bit): top of the fridge, top of the windows, top of everything, then all the surfaces and things sitting on them and finally dust bunnies. While dusting we gather all the things that are out of place on the couch or in a contained pile so that we can clean around them. We'll worry about putting them away last (or even the following weekend). We keep a trash bag on hand to toss anything known to be a trash and keep a separate pile for donations.
This is how we get momentum going and why we're glad we live in a small space since there's less to dust. How do you kick off your spring cleaning? Do you tackle it all in a weekend, or allow it to happen throughout the spring? What do you start with?