With music, I go for whatever tickles me fancy

, and check out recommendations on Youtube. Actually I don't buy music... :/ Just listen to them on Youtube now and then.
With movies, I would go with recommendations and reviews of people I trust to have good critical views on things, but also mixed with my own preferences.
With books, I'm more fussy, go with it based on the topic, the preview and sometimes I check out the background of the author, but I do check reviews too just to make sure there isn't something hugely negative about it talked about many people.
Sometimes I recommend books to people which I wouldn't personally read, but think it might be good for them...after a quick look at it, and suggest it might be of interest to them.