I have multiple vehicles and thus multiple sets of keys, I realized I had too many keys if I kept them all together and the possibility of loosing all my keys at once was a fear. So I made a bunch of copies of my House key and made multiple key rings:
I have a keyring for the Truck that has the Truck keys + a House key.
I have a keyring for my Honda Fit that has my Fit Key + a House key + The Mail keys as I always go get mail with the Fit.
I have a keyring for my Stella that is the Stella Key + a House key.
I have a keyring for my Yamaha that is the Yamaha Key + a House key.
I have a keyring that has my Shed Key + a House key.
So, with the exception of the Fit Key Ring having the Mail keys I always have the minimum keys needed to get to my other key sets which I keep in my house.