Find a scope you like. For me I stick with medium ranged scopes. Short range scopes are too jumpy and and long range limits you field of view. Also find a sniper you like and stick with it. I personally like high impact snipers. High impact allows you to oneshot a fully shielded player with a headshot. Great for punishing revives, blade dancers, and radiance. It also allows you to get one shot kills with bodyshots if your target has their shields partially downed. One of the "ah hah" moments I had with sniping back in the day was using strafing to aim. Get your crosshairs at head height and strafe left and right to aim.