Photo is a good idea, because i used to received a message asking me whether is this profile real or not because very less photo...people nowadays are smart
Beside that what i did was, i play around with keyword.
For example I create an account and i put Texas as hometown and Citibank as employer. So i scrap those people that are from Texas and also from Citibank, then i send them a message saying "Hai dear, I'm from Texas bla bla bla bla" and the other one is a message about Citibank.
Because before they going to click accept invitation (or whatever), they will open the profile first to view and read about you. If they saw something that is in common or that can attract them then the chances are high for them to accept you.
Look for a big group, huge company or large population area....maybe in your profile you can put something like Yale Alumni or PeaceCorp or anything...
In another way, you can get a targeted friend by doing this