The Missoula Nordic Ski Club demonstrates a basic technique of classic skiing:
Striding (or 'diagonal stride') - it's like a low gear for starting, easy skiing, and uphills
More technique videos
Overview of All Four Techniques: https://youtu.be/4aQVNyY52Pc
Striding: https://youtu.be/6NST1N6-P28
Herringbone: https://youtu.be/JdvUibe750k
Double Pole: https://youtu.be/BBa2fPziRl0
Kick Double Pole: https://youtu.be/a7itYppe8xk
Grip: https://youtu.be/I8iGqr9ZZN0
Filmed at Lolo Pass on the Montana/Idaho border
