Decants into small 5ml/8ml/10ml etc. atomizers seems like the most logical option. You easily decant something into one of these by just buying a decanting kit.
Basically if you want to decant from a proper bottle into a smaller atomizer, just get a tiny funnel and use that to spray into the smaller atomizer. Seems like quite an arduous task, but it actually doesn't take TOO long if the sprayer is half decent.