Taking photos of each base with its model is a nice reference for the future. No need to go guessing which figure goes to which base :)
And once the paint was dry and the green stuff was mostly cured, it was time to add the water to my streams and puddles.
I used Envirotex Lite, mixed as instructed in 1:1 ratio, covered the whole work area with a nylon bag, and started carefuly pouring the mix. If some of the mix gets on the lip of the base its fine. it can always be painted over :)