Racers and Gatekeepers should review all this information about hiking around single and double pole gates by watching the below video.
Please note that the first and last gates will always be double pole gates which are also called closed gates, and in SL there will be a few additional double pole gates (fancy names: flush, hairpins, delays).
With double pole gates the racer's boots need to cross the plane between two poles that are the same color. They can cross in either direction. Over and back is okay, too, for double pole gates.
Proper gate passage / hiking missed gates:
https://youtu.be/R6dKPt0DAn4
Judging gate passage:
https://youtu.be/t22dyCkQZQM?si=rkEh1cLUgPeAKfvn
Proper form for slalom racing, some technique, and getting in the flow:
https://youtu.be/HS-AOjkSqRc
Video of Mikaela Shiffrin's World Championship Slalom win, with video and diagrams of proper slalom gate passage in open gates and vertical combinations--hairpins and flushes--and discussion/diagram of hiking:
https://youtu.be/nO7An8NfwMw
Video for racers who are cross-blocking slalom gates to view in order to learn/work on outside hand blocking, especially when exiting combinations & a discussion of combinations generally.
https://youtu.be/rFZAqWR-JgQ