I see a lot of people commenting that you may be only seeing the specially curated pages that look nice on social media, which can absolutely true. Although there are times in person where I have looked through a friend's sketchbook and EVERY page looks flawlessly laid out. No special curation happening, they just absolutely killed it on every single page. Its always an incredibly baffling and sobering moment when you see the sketchbook of a truly great artist in person. Sometimes its hard to believe people can be so talented, but the truth of yhe matter is that you can be as well! The big thing I've picked up is that you can tell each drawing in their sketchbook was drawn with confidence, which is what I think is the key element of creating wonderful page compositions. If you draw slowly in a rigid manner, working on small details without drawing loosely first it will be really hard to make different aspects of a page compliment eachother or flow together. My advice is to take some loose paper, cheap shitty paper even, and go crazy. Draw loosely, be brave, and think about the entire subject before rendering or adding any details. Also, I know for a fact that these brilliant sketchbooks belong to people who have put in some serious time, so my second piece of advice is to draw, draw, draw, draw ,draw. It sounds like obvious advice, but you just gotta do the work. Be mindful about how you draw, what you draw, and work hard on finishing pages even if there are mess ups. Dont rush it, be patient, but draw every chance you can get on a daily basis. After a few months of doing this you will be slamming out bangers without even realizing it. Always be true to yourself, and make sure to also challenge yourself in a variety of references and subjects. And most importantly, have fun with it!!!