The easiest way to set up a problem is to simply make a list of the given data with units, labels, and any reactions. You should also indicate what is to be found. The act of writing out the data and relevant reactions will help you in two different ways. First, it is a systematic way to start thinking about a problem. Second, it is a good way to discover and remember the patterns that underlie problem solutions.
Most students realize that problems fall into patterns by looking at the examples in the text.
That is, if you are stuck on a problem, you look for one that resembles it in the text. Actually, this does seem to make sense because the ability to assign a category to a problem has been found to be a characteristic of expertise in problem solving. You may not realize, however, that ability is best developed via active construction rather than via passive recognition. In other words, simply looking for a similar problem does not really help you to learn how the different elements work together. Setting up problems is one system that can help you construct a set of problem categories that will be more flexible and lead to a more comprehensive understanding of the material.