STAR WARS™: Squadrons Drifting Guide

1. Transfer all power to engines (hit “1”)
2. Boost (hit “SPACE” on keyboard, “L3” on controller) straight ahead
3. Then – while the boost is still active – move your mouse all the way to one side whilst hitting “shift” on the keyboard or “L3” on the controller.

Pics and a short video will soon be added.

Someone was kind enough to share the following guide as well:
https://www.ea.com/games/starwars/squadrons/tips-and-tricks/how-to-boost-and-drift-in-star-wars-squadronsThis is what they say:

“There’s a number of tricks that ace pilots can pull to get out of dangerous situations and to gain an advantage over their opponents in Star Wars™: Squadrons. Boost and drift are two such maneuvers.

HOW TO BOOST
Boost must first be made available by overcharging your engines. Press D-pad left / 1 / POV west to transfer power to your engines. When the blue engine power bar is full, a yellow meter will start to fill, representing the amount of boost that will be available; the more the gauge is filled, the longer you can boost. Once there is some charge in the meter, you can click the left thumbstick / L3 / press Space / JOY 9 to initiate the boost. The yellow boost meter will start to drain, and when it is empty the boost will disengage automatically. You can disengage the boost manually at any time by clicking the left thumbstick / L3 / press Space / JOY 9 a second time. Note that although boost will grant you an enormous burst of speed, maneuverability will be significantly reduced.

HOW TO DRIFT
Now that you have learned how to overcharge the engines and boost, the next step is to learn how to drift. While boosting, you can click and hold the left thumbstick / L3 / press and hold Shift / JOY 9 and turn your ship in any direction with the right thumbstick / R3 / Mouse X axis / JOY 0 axis. Your ship will continue on its current heading but you will have a brief period of directional control that will allow you to fire perpendicular to your direction of travel, spin around 180 degrees and fire on a tailing enemy or shoot down an incoming missile. Or, you can trigger another boost (provided there is still charge in the boost meter) and perform a sharp 90-degree turn around an obstacle to shake pursuit or evade a missile.”