Inclinare LA testa ...
Un piccolo passo indietro.
(never say that to a model on the ridge of the Grand Canyon, or
on a shelf of rock in the breathtaking view of the Dolomite mountains;
the typical Italian model won't forgive you, not in a million years!).
Everything else is ok.
Directions to give poeple
Inclinare il la testa a sinistra / destra
(Tilt your head to the left / right)
Un pass indictor un po’ Va' un po' più indietro
(Step back a little)
Fare Fa' un grande passo in avanti
(Take a big step forward)
Directions to give poeple
Inclina la testa a sinistra / destra ( "Inclinare" isn't wrong, but it is the infinitive forme=to tilt. You wrote " tilt your head" so you can say "Inclina..." or in formal way "Inclini..." )
(Tilt your head to the left / right)
Un piccolo passo indietro / fai/fa' un piccolo passo indietro/ Vai/va' un poco indietro .( In formal way: Vada un poco indietro, per favore/ faccia un piccolo passo indietro , per favore)
(Step back a little)
Fare un grande passo in avanti / fai / fa' ....etc. ( fa'= fai)
(Take a big step forward)