I've also decluttered people, both on purpose and not on purpose. In high-school, I cut off ties with a circle of friends who were badmouthing me behind my back, though I regret simply not talking to them anymore -- I should have told them why I wasn't. And within the last years, I decluttered two more people -- with both, there was a situation that I was initially to mad and/or insulted about to be able to handle it like I should have (read: as I would now), and when I wanted to save the friendship, they didn't want to. Turns out I haven't missed them one bit, so it was a good life lesson for me :o)
To answer your question, RJ: I guess it depends on how annoying this woman is for you. It depends on whether you think she deserves to know the reason for you trying to get away from this contact. If you think she does, just tell her matter-of-factly. So for example, if she's an egoist and never listens to you, just tell her that with her need to talk about herself, there seems to be no room for you in the friendship, and that there seem to be different views of what a friendship should be in her eyes and your eyes, and thus you don't think you want to continue it. If, however, you think she's a perfectly good person, you don't want to hurt her feelings, but you two are just not that compatible, keep coming up with excuses for not meeting her. She'll eventually get the hint (I hope!).
Though now I wonder: If it was me, what would I like to have done to myself? Being told right-away and getting hurt immediately, or being repeatedly rejected and getting hurt in the long run when I realize what this is about? I don't know. I guess it would depend on the person who tries to cut off the friendship and how he/she does it. What do you guys think?
Do you know these threads yet?
* Cluttery-Guests :(, inspiring in respect to finally setting boundaries with someone -- have you seen this thread, SunshineR?
* Uncluttering bad/toxic friends is on how to end a friendship. Oh, I'm glad they finally got it, themusiclivez! :o)