When I'm trying to wee and struggling to get started I picture a specific scene from Blake's 7 where Tarrant has to pull a lever to open a dam. Usually does the trick
@fesshole when I was a student my room was in an annexe of a hairdressers. The (very 1980s) decor included a fully mirror-tiled tiny under-stairs toilet where you could see infinite reflections of yourself from all angles in painful detail while listening to all the old ladies gossip in the salon. The way to relax myself into taking a pee was to close my eyes and visualise the video for TLC's "Waterfall" while quietly humming the tune to myself.
Still works now if I'm a little tense! 😀