1. Declutter Just a Bit. Find a new place for -- or better yet, get rid of -- anything that does not belong in the room but is visible. (Save the stuff behind closed doors for another day. You don't want to get overwhelmed.) Clearing the clutter makes deep cleaning easier, plus seeing those tidy surfaces will give you the oomph to keep going.
2. Start High, Go Low. Tackle the big, hard-to-reach surfaces in this order: ceiling, ceiling trim, ceiling light fixtures (including bulbs), walls, the rest of the trim, and baseboards. The best tool is a clean microfiber mop or duster with a telescoping handle. (They're so thin you can get behind the sofa without moving it.) Above eye level, a spritz of water is all you need on the mop. But below, where there is actual dirt plus dust, use warm water mixed with a drop of dish soap. (In bathrooms, add a splash of white vinegar to stop mold.) Where a mop is unwieldy, use a microfiber cloth. Rinse often and wring thoroughly.
3. Yep, You Do Windows. It's not that bad, and the payoff is huge. First, vacuum the sills and tracks. Then spritz the window with cleaner from top to bottom. Let the cleaner do its thing for a minute, then squeegee it off. If you wipe in one direction on inside windows and another on outside ones, it will be easier to see and fix streaks.
4. Spruce Up Those Window Treatments. Save yourself the trouble of taking down blinds or shades. All you really need to do is vacuum them using the brush attachment. And instead of laundering and ironing curtains, just fluff them in the dryer for a few minutes (while you wipe off the rod and rings). Then hang them right back up.
5. Ditch the Dust. Wipe all remaining hard surfaces (wood furniture, shelves, built-ins, etc.) using a petroleum distillate-free, beeswax-based wood cleaner. (Try Williamsville Wax, $6.25; hfstaples.com.) If you feel the need for speed, put a clean cotton tube sock on your dominant hand and move objects with the other. Finally, take a lint roller to the lampshades.
6. Refresh Those Floors. Folks, to do this right, you've gotta move the furniture, even the biggies like beds and sofas. To make that easier now and in the future, put furniture gliders (about $5 for four; amazon.com) under the big pieces. Then break out your vacuum's crevice tool to get at dirt in corners and along baseboards. If you have a hard floor, clean it with a microfiber mop and the prescribed cleaner. If you have carpet, now is a good time to rent a professional-grade cleaner. (And if you have pets and/or kids, think about investing in your own.)