One of the most common questions that I tend to get asked by my students is about the skill of evaluation, when it comes to exam questions. The most important point that I explain to them that it is the same skill in Business as it is in History, Geography, English or Science. It doesn't matter which subject you are studying the skill of evaluation is exactly the same. It is why I believe that you have to teach this as a skill and then make use of this skill in all the subjects that you study.
The other key point to note is how evaluation is pointless if you don't understand the basic knowledge that is required to make your evaluative answer. This is because you need to use the knowledge and apply the knowledge to perform a decent evaluation. This is why practicing evaluative questions is totally pointless until you understand the knowledge required.
Below you can find links for two videos that I have produced. Each gives you a question and then takes you through the skills required to produce a good answer.
Tackling the Evaluative Question 1
Tackling the Evaluative Question 2