Save up on the Hold Breath feature by cancelling it as soon as you make the shot. If you do this every time, you will be able to use it throughout the level, without waiting for a refill.

You can earn more points by being creative, so observe the targets and regular people carefully before taking any shots.

Once you complete the primary objective, all optional ones disappear so try to do them first.

In case you mess up and kill the main target first, use the Hold Breath feature to beat the clock and execute the secondary target in those few precious seconds.

Use the purple marker to mark a person of interest and keep an eye out on his movement.

A double headshot or some other creative kill will get you a lot more points, so keep your eyes open.

There is a secret rubber duck on the roof of the main building that you can find to get more points. There are also 5 hidden laptops around the map, but one of them is only visible in the night.

The text that comes up during the loading screen is almost always full of helpful information.