Boundaries how-to?

One thing my encounter with an N highlighted was that I am not so good at setting and enforcing boundaries with people close to me. My mother has always hated them, so this is a family of origin problem. I can be pretty compliant: people want, I try to give it to them if I can. Sometimes this is just being agreeable, but sometimes it's just bad boundary-setting.
Case in point, a friend recently came to visit for the holidays and announced that she'd taken video of my apartment while I was gone, as a souvenir. I told her that that made me uncomfortable, as did some video she took of me before I knew the camera was on. OK, so boundary announced. But my friend made no offer to delete the video. I asked her not to show it to anyone, I think...
How does boundary-setting go after you've announced your boundaries? Are there supposed to be some consequences if someone violates them? I wasn't about to make a big deal of the video, because I'm not one to pout publicly, but how do we make our boundaries clear besides telling people where they are?
This should be basic stuff, I know. But in my family, boundaries and privacy were treated like signs of secrecy and guilt.
Thanks all.