I think the only way you could enjoy studying would be if you really liked your subjects. It depends on the individual but different techniques can be fun. You might enjoy constructing visual representations of information, i.e. mind-maps, posters, diagrams, etc. I know as a History student, I also like writing; so as a 'fun' way to study I write a narrative that coincides with the content I learn in History (helpful for both History and English!). Other ways could be to create songs, acronyms, metaphors for the content. My Ancient Class in particular last year studied Roman society so my teacher made Roman society applicable to our school environment, so different positions correlated to different Roman positions and terms (was great for learning terminology for the period). Not sure if I helped, and I do apologise that my information is more History orientated, it's the only subject I enjoy studying for; and these are the sorts of things I do to make it fun for me. Sure beats the monotony of 4 hours of reading and summarising information.