How does trickle down economics work?

I read on my favourite Conservative blog that Trump's tax cut will make everyone richer. Like if you give rich people more money then they have more money than everyone else so everyone is rich. I wanna believe this but I'm real confused.

Do these folks go out and be 'job creators' hiring more nannies? I mean what if they just wanna keep the dough or buy a house? Or what if businesses have enough workers? I know Government wastes money and sh*t but I just don't get how wealth is supposed to trickle-down.