Depending on your exam board, you may be asked to compare different texts you study either in an exam or in your coursework. The first, and most important, thing to consider before starting your comparison is which texts to compare. While you may feel inclined to pick texts which are obviously similar, so you have a lot of points to compare, usually it is best to find texts which will have one main point of comparison which you can centre your question around. Possible points of comparison can include common themes, such as family, women, age, war, money ect. However, it is adisable to stay away from very broad themes such as relationships. In fact, considering the word limits for such pieces, it is usually best to pick quite a specific theme, such as the weather or music for example. While this may seem more difficult, it is far easier to write in detail about a specific comparison than trying to address something as broad as relationships in two texts in 1500 words. 

While this is not a priority in picking your texts, I personally found it easier to compare tetxs that were reasonably short. This way I was able to re-read the texts so I knew them really well and was able to find quotes quickly to support my points. It also meant I could address the text as a whole rather than only knowing one section thoroughly and not being able to link this to a wider reading.