Once you have brainstormed (or morphologically analysed) your problem the preferred solution might be easy to spot. If it isn’t here is one technique to help you evaluate the outcomes and make a decision. There are more ideas in the table here.
Paired comparison analysis
In this technique you compare each potential solution to each other potential solution and choose the one you prefer in each case. The preferred solution is given a score of 1, 2 or 3 depending on just how much you prefer it (higher scores for higher preference). The highest scoring suggestion is the preferred option. You could work on this individually and combine everyones scores at the end.