I put my containers on makeshift tables/shelves. My main reason is that I don't want to bend down to peak if the containers were placed on the ground. Another benefit is that slugs cannot get to my seedlings. :-)

I collected a couple futon headboards that people discarded in the alley behind my house. I set them on saw horses or upside down 5 gallon buckets like so:
{{gwi:435220}}

Pretty, huh? Just ignore my messy jugs.
:-)