Best vibration tweaks

The components in my system rest on a Lovan rack (not filled). Until recently, I hadn't considered doing much more to control vibrations in my system. But I've noticed that their are some relatively inexpensive (a dangerous phrase in our hobby) tweaks in this department that are available. I'm curious to know what experience others have had with things like Vibrapods, filling their stands with weighted material, airmats, Audiopoints (?), those half-globe gel balls (don't know their name), etc. If you've tried them, how much of an improvement (if any) did they make? Several of these appear to be mutually exclusive, so which do you recommend most? Thanks for your input.