nedleycan.....no strategy needed. Just jump in any line that you want for photos. There are about three different lines in the atrium for formal photos, semi-formal, each with different characters. They have different backgrounds and characters on different nights.
See who's in the atrium area and just stand in the line with the character or backdrop that you want in your picture. If you don't want any pictures, don't stand in line. Very easy. You don't need to sign up or reserve them or anything. Totally your choice.
In the dining rooms and around the ship, the photographers come around and ask you if you want your photo taken. If you do say yes, if you don't say no thank you and they will move on.
MJ