Adjusting for Tweeter height with monitors

This may be a dumb question but how do you guys go about making sure your ears and tweeters are properly aligned?  After all, stands only come in a few sizes. Do you use height-adjustable chairs? 

I have to raise my Silverline monitors high enough to ensure the woofers clear obstructing furniture and in so doing, the tweeters end up about 4 inches higher than ear-level, when seated, which has a negative sonic effect. Rising up out of my chair a few inches, the sound is much better. My wife has volunteered to make me a tall seat cushion to compensate but this makes me wonder how others approach this.