Just use your name, you're trying to sell yourself in this business. You want people to say Blair Whoever took my photo's and they turned out awesome!!! Then your name will get around and you'll be known. Take a look at all the greats, you can mention them in passing conversation with other photographers and they're usually known easily enough. How many times do you hear the worlds top photographers hiding behind a business name?
As for "photos by Blair" I would stay away from it, IMO it's tacky and amateur, but thats just me. Try (as said here previously) simply 'Blair' or 'Blair Whateveryournameis'. I chose 'Chris Mallet Photography' as my official business name, but a lot of the time I leave photography out just because I can. Either use your name and brand you... or, brand yourself like a corporation "GAP" "BURBERRY" "CHANEL". Simple, easy to remember, classy, timeless.