the game is very good and you will never get boring of this game I ensure that.
-Security Bullseye: Especially in earlier levels this can be your Big Daddy Killer. Before you have access to electric gel, grenades, mines, lots of Armor Piercing Ammo you can use this plasmid to have Rapture itself take out the tougher enemies.
-Telekinesis: This is the best offensive plasmid available, no doubt. Especially on the harder difficulty settings when ammo is either at a premium or takes forever to take down an enemy. Plus it has all kinds of other uses, picking up a corpse and using it as a shield, getting hard to reach items, starting fires with explosions etc....
-For good camera shots, try to get the enemy to fill up the space without the enemny being out of frame. Get them centered, and preferable doing an actio, i.e: take a picture when a Thuggish Splicer goes to attack you. You can get bonuses such as multiple subjects and action shot which help boost the grade of your photo.
I recommended this game for playing and I hope I give a good hint about it.