Two of them are exclusively for perusal of my friends list. One is the Default View, which everyone is on anyway, and one is Must-Reads, for when I am away from regular internet access, e.g. on holiday. The people on Must-Reads are mostly real-life friends, although there are some exceptions. And truthfully, I hardly ever use it, because, as I mentioned before, I am an addict.
I don't keep communities or feeds on my friends list. Those are all in Bookmarks folders along with the people whose journals I read but don't feel comfortable adding as friends.
I have one filter for writing, which is going to see heavy usage once NaNoWriMo comes around again and is somewhat opt-in, although I do remove people fairly readily if they prove unresponsive.
Four filters are exclusively content-based. One is a broad filter that includes almost everyone on my friends list and is opt-in by request if you're not already on it. Two include the people I feel I can trust with certain types of personal issues. Those are semi-opt-in. The last has a very small number of people and is not opt-in. All filters are opt-out should anyone feel discomfort with the contents of my posts.
I'm curious about the way other people safeguard their privacy, both on LJ and off. I realize it's a bit anachronistic to even be asking these questions, but the poll results are only viewable to me, and if you're not comfortable sharing, then by all means don't answer.
Do you use the filter function on LiveJournal?
If you use filters, what is their purpose?
Do you keep a separate journal?
If you keep a separate journal, what format(s) do you use?
Nigella vs. Martha: fight!