When creating the poster map of a country which includes major landforms, natural resources, and large cities, go ahead and spend the $7 at Walmart and buy the whole coffee beans to glue on to represent the coffee resource of that country.
Do NOT try to use the instant coffee grains you already have at home. When mixed with glue, they just make little puddles of sticky coffee instead of actually looking and smelling like coffee. You may end up with little brown wet splotches that make the countries look like they are mining miniature cow ploppers. (Am I allowed to say cow ploppers on a family blog?!)
Trust me. This is good advice.