You drift by holding LT while accelerating (RT). You can use the left stick to control your drift somewhat. The easiest and earliest opportunity for this is the Rogue's Landing stage.
The flight sections are fairly wide open, and if you really just want to get this achievement you can simply just drift in a continuous circle until the you charge a level 3 boost. Achievement pops immediately.
Note: If you have flight assist turned on, please disable it as you can't turn in circles with it on.