Raising the nosewheel on takeoff
Centaurus - Before solo on single seat Vampires, we were shown the correct attitude by sitting some guys on the tailboom, and then the attitude that would scrape the tail.
Other aircraft; noting the horizon attitude that the nosewheel stopped rumbling.
All JP's had nosewheel u/c, but the JP 1's had longer u/c legs as I think they used Piston Provost legs initially.