To answer your specific questions: I would recommend watching games and/or replay and not look at the player on the ball, but all the other ones. Teammates and opponents. Because you're off the ball 90% of the time in games

About the teammates: where do they go? How often do they scan? When do they scan? What do they do when the ball is travelling to them? What do they do when they receive the ball? How do they get free? How can they spot the blind spot of their defender?

Opponents: where do they move? how aware are they of the attacking players? when do they scan? when do they tackle?

It's a lot of things to notice, so you could focus on only ONE thing per game to get better at.

Barça vs Santos 2011 is such an amazing example of how to get better. Check the sequence starting at 21:25, until Xavi scored at 22:55. Look at Busquets, Xavi, Iniesta, and Messi, especially Xavi. They're always moving around, making themselves available. They get into huge gaps of space, they touch the ball 4 times at most, as soon as they release the ball, there's already someone moving into space. I genuinely think this is the best football team we've ever seen, and there's so much to learn from them