Lookout

Lookouts are the masters of seeing without being seen.  The can gain cover where there seems to be none and see and hear things that seem to be too far away.  They leverage these skills to make excellent ranged attacks.

Sniper's Perch

Starting at 3rd level,  you can use sneak attack on ranged attacks you make from at least 10 ft. above the target.

Eagle Eye

You gain proficiency in the Perception  if you don't already have it.  If you do you gain expertise in proficiency.  You have advantage on Perception checks to see objects 100 ft. or more away.

Scrambler

At 9th level, you gain a climbing speed equal to your movement speed.  As a bonus action, you can spend half your movement speed to secure yourself to a vertical surface so that you can see behind you and use both hands to manipulate objects, cast spells and make weapon attacks.  The effect ends when you leave that position.

Camouflage Expert

Starting at 13th level, you excel at disappearing into the background.

You have advantage on ranged attacks made when you have half cover or more from the target. You may use your bonus action to make a stealth check to hide even when you are partially visible to the creature(s) you are hiding from.  You have disadvantage on this check unless you are at least 60 ft. away from any hostile creature that can see you.

Punishing Barrage

When you deal sneak attack damage with a ranged attack, you may make two additional ranged attacks against different targets as part of the same action.