I've been using a Palomar knot on frogs & haven't had a slippage problem. Scott Green told me he also ties a Palomar for frogs. I have read that its strength isn't as good as some other knots, but I haven't had a slippage problem.

For buzzbaits, I use a doubled-over uniknot (I think that's what it's called) that Todd showed me. Seems like you only have to wrap the line over itself three times to get a secure knot. I also went to scissors for cutting the tag ends, & that works way better than the regular clippers I use for mono.