I'm personally not really able to see immediately who made a photograph, unless I already know it from studying.
But, honestly, I've always been a bit allergic to the word 'style', because to me it becomes one of those things that photographers try to accomplish, to 'create' a style for themselves and not be patient enough to simply let it evolve. That, I think, can be a great distraction, and maybe even a source of disappointment, because they try so hard to comply with their 'style'.
To me it's better to just not worry about style, work those prints, and if we work hard and look within ourselves to find out what we want our work to come across like, that 'style' will simply come naturally.
Some photographers I think have a real mark on the photography world, though, like H. Cartier-Bresson, P. Strand, A. Adams, whose work is pretty unmistakable. They practiced a bit, didn't they?