To be honest, I've found that I prefer using YouTube to learn new techniques - for example, when I want to try increases or a specific stitch pattern for the first time, watching someone do it on video just helps me the most. For more complex projects, though, I do go back to purchased patterns because they're usually better organized and I can look things up faster if I have questions, without having to fast-forward through a 20-minute video. Honestly, the best approach would probably be to first check YouTube and see if you like a particular YouTuber's style, and then buy magazines or pattern books when you realize you work better with them - doesn't have to be one or the other 😊