In some cases I keep em, not too often though... It really depends on the toy, and of course until I have reviewed something it rarely stays without the package it came in...
I have a tendency to hoard packaging. As in I am an actual hoarder. It stays around awhile until I can force myself to let it go. Thankfully I have gotten myself to the point where that period of time is between two weeks and one month. I used to hang on to it for years before I started therapy.
If it's particularly cute or if it's really useful for storing the toy (or if I can find an alternate use for it, like the Evolved tins), I might keep it for awhile, but I eventually end up getting rid of it.
Right now I am keeping them all because I have the space. I will probably get rid of some soon though. The Tantus ones especially are not likely to be used ever again.
It depends. If it looks nice or I can put some cute fabric on it and turn it into a hinged gift box like the Lelo boxes and sell it or give it as a present.
If it comes in a cloth bag or a fancy box (njoy plug)...... or a nice tube thing (mustang).....I don't keep paper packaging (oh snap except for my ophoria, it didn't come with a bag and the foam insert thing is too convenient).
So far I think I've kept almost all of my packages. However I don't have that much yet so when space becomes a problem I'll probably start throwing the larger, older and cheaper packaging away.