If you want to spice up your strumming, or if you don’t know the chords when we're jamming or the changes are too fast, you can play the Z chord. You do that by covering the strings gently with your chording hand so that they don’t make any sound - just a percussive sound when you strum. You’ll see what I mean around the 0:57 mark in the video below.
Z Chord and other fancy ukulele strumming
Insert the Z chord into normal up-down-up-down strumming to create really interesting rhythms without having to do anything fancy with your strumming hand