I'm a collector as well as an artist. I've been collecting for about 40 years — photographs, paintings, sculpture and glass in particular. For me, the initial impression of a work is like the first sip of wine. It will get my attention. Then I swill it around in my brain for a while, step back, step closer, and if it still resonates after a while, I'll buy it.
There is more than one approach to collecting. I for one do not have what you would describe as a cohesive collection. I place pieces in my space with consideration as to how they work together - that is important to me - the common thread is that they bring me joy.
Art glass with photographs
Another approach: focus your art photography collection on a few artists (feel free to make me one of them). Some collectors find an emerging artist and purchase their work as their reputation grows.
Series: Paris, Florence & Amalfi
Others collect well-known 20th century works by photographers like Man Ray, Diane Arbus, Mapplethorpe, Cartier-Bresson and always, Ansel Adams. If you love what you collect, either approach is the right one.