We have a catnip spray that we spritz occasionally on some small stuffed toys. Once or twice a week.
One time I found a bottle of bubbles at Pet Smart that had catnip in it. One of our cats would jump five feet after those bubbles! It was hilarious. I have never found it again. STBDH (soon-to-be DH) tried making some but it never worked the same plus was afraid it would stain things. (The one from Pet Smart said it wouldn't stain and never did.)