Like Mrs NB I found having a big cry helped - I had an attempted stretch and sweep at 40+5, returned for a second at 40+6 and the horrible MW told me it'd be useless as I was clearly not ready to birth this baby, baby was high, not engaged blah blah and I should just be patient

Went home, had a big cry, first contraction at 3am, baby born 9am

ETA: He was also a big one - 4.84kg!