I have two who (combined) do this.
Spooky likes to knock glasses over. My solution was to buy everything in resealable bottles, and wash and reuse those, mainly for water. I bought a few of these cups (http://www.laprimashops.com/Zak-Chil..._p_20-849.html
) which are designed for kids that resist spilling when knocked over, though they arenâ€™t spill-proof and they will still leak some if you leave them toppled, its only a few drops vs. the whole glass.
Mulder likes to play and splash all the water out of his water bowl and when possible turn it over. I got them a water bottle and am working on training them to drink from that so I donâ€™t have to leave a water bowl out for them to spill. I have them going to the bottle about Â½ of the time. Not sure if that is a viable answer for you. I posted about it here (http://www.thecatsite.com/forums/sho...d.php?t=183270
I have noticed Spooky has really cut back on knocking over drinks since heâ€™s figured out they donâ€™t spill when he does, and Mulder has been splashing the bowl less often (though not stopped completely) since I started the water bottle training.
I wish you the best of luck with your kitty!