Danica, Slovenia
I know what you are talking about. It's not always easy, particularly when it's not the same in your language. But in most cases, when you ask about quantity for countable, you get a number as an answer. If uncountable, there must be something else (containers, units...) The funny thing is when I say to students that we cannot count money...but we get that clear, too...

Julia, Switzerland
Take in kitchen articles, coffee, tea, sugar, spoons, cups, all those things. The good thing is they all come in jars, packets, bags, etc.. Teach basic some and any, there is, there are, singular, plural as usual, now use realia to let the students make negatives, questions, positives, plus they get a visual idea as to why coffee is singular but coffee beans are plural. Do the same with tea and tea bags and so on, sugar, sugar lumps, and finally, finish off the lesson by having tea or coffee together.

Steve Bowen, The Netherlands
As far as I know, all nouns which are countable and where a choice has
to be made between 'much' and 'many' or 'some' and 'any' are plural. One
exception comes to mind: 'people', a single noun which has a plural meaning
(and is countable). I try and avoid the issue of countable and uncountable
nouns because it's more confusing to my students than the simpler to grasp singular/plural explanation. (One item is also countable and, as another contributor stated, so is money/cash.)