it has always been my contention that the best way to install an exhibition of paintings, prints, photographs (or a collection of all three), is to use your eye and not a tape measure. you are creating a dialogue (or even an argument), but more than likely a conversation between the art, the artists, and the viewers that will blossom more freely if the structure of the installation is less rigid and more natural.
there are those in the art world who would differ with me on this subject, but i can finally announce some vindication by quoting nick serota of the tate modern (and all of the tates: britain, liverpool, et al): “working with david [david sylvester, writer and critic), was a pretty special experience. i learned not to use a tape measure when installing, for starters. use your eye.” (via the july 2, 2012 the new yorker‘s calvin tomkins “the modern man” profile of serota). not that that statement is the be-all, end-all, but it is nick serota after all, and his opinion should carry some weight with my detractors.