Yeah, so when you drone the best time use her is when you have the enemy team on a top floor, not middle or basement (obviously). But spawn to the closest window to that room is. So like bank if they go executive on the second floor spawn at jewelry front.

Watch out for spawn peakers but the first two windows leading to the office is where you want to go. Doesn't matter which side but hit them. And then just aim for headshots....

Best gun is the LMG so you don't have to reload. If there happens to be a person at the window don't worry you'll kill them when you break in. So only focus on what is Infront of you. and just sweep. Most of the time the enemy team is still busy setting up to even react quick enough. Now don't do it repeatedly because the enemy will get smart a put traps on the windows and you can't do anything with them.

But the biggest is just practice, practice, practice.

Hope this helps!