Think of your home as a boutique hotel: the rooms are comfortable with high-quality, carefully chosen accoutrements. Far from being stark white boxes, they are a very inviting place to "move into" right now -- the very same feeling you want prospective buyers to feel in your home. The lesson is that neutral does not mean "not lived in."
Your home will be more welcoming if looks "finished" in an inoffensive way. Buyers don't want windows to be obscured with heavy dated drapes, but they also don't want them to be bare. Install light gauzy window coverings. Edit your furnishings so that rooms look bigger, but keep enough of the basics so that there's a good conversational grouping in the living room, good reading lamps next to the beds in the bedrooms, high-quality towels in the bathroom.
Contrary to popular opinion, white is not the greatest color for your home's walls. Not only is it a bit harsh and unflattering, it can actually draw attention to flaws, such as uneven walls or cracks. So when you're trying to "tone down" your home so that it's more broadly appealing, think soothing colors that are on the second or third step on most color fans of paint chips. Beige, in particular, is a nice choice. Far from being boring, it comes in a range of interesting softer shades from latte to cappuccino to cocoa, and it coordinates well with other popular colors including soft aqua, powder blue, or pale tangerine.
You know that taking things out of your home will help make it look bigger, but you don't want to strip it completely of its personality. The "new neutral" requires editing, but still allows some of your sense of style to come through. If you are a duck lover, for example, you may want to tone down the theme in your den by removing the duck pillows, the rug with the flying ducks, and the world's largest collection of duck prints and decoys. Instead, aim to create restrained and inviting vignettes. Keep most of the furnishings neutral but hang your best duck print above the fireplace and place a beautiful vintage decoy on the mantel. The goal is for your home to look "done" (as opposed to being an empty shell) but without offending anybody's color palette or sense of style.