What function would be useful to add variety to an expression over time? I have something rotating at $FF*30 but I would like this to vary over time.

In my current project I will actually need to do this ALOT on transforms and other things too as I have a lot of seperate geo that needs to do things but not all the same.

Add noise() to a suitable location in your expression. E.g. $FF * 10 + 100 * noise(0.1 * $FF,0.1,0.91)

thanks