If you saw my house, you wouldn't want my advice. However, since I do understand the problem, I will tell you that what works for me is defining a specific task: e.g., clean a particular closet or drawer.

I adore Freecycle, though you don't get a tax benefit and occasionally people don't turn up when they say they will. But it's wonderful for getting rid of "special interest" items and I've gotten warm thank-you notes which makes the entire process less annoying.