Thanks for the replies so far, everyone.
Basically, what I mean is, all the how-to guides go on about the importance of developing a thesis behind the concept, eg, Belonging, and then discussing techniques and effects. No mention of themes.by themes, I am talking mostly about issues that are prevalent to the texts, eg isolation, identity etc..., eg you might talk about the thesis, then underlying themes that convey the thesis, then techniques, effects etc...