re: beer mug!

Ah, I see!
You could pipe some piping gel, if you use a very small icing tip you could get the same effect, also for even smaller droplets you could use the end of a cocktail stick dipped in piping gel.

I haven’t tested any of these myself, but its what I would do to create the effect you are looking for. What ever you decide, make sure to test it on a separate piece of fondant first instead of straight on to the cake, I can’t tell you how many times I’ve made that mistake, but, you probably knew that anyway :)

If there is any other way to create the effect I would love to know.

Hope this helps!! Xx