Watching your game back isn't the same as reviewing it. A good review is short, focused, and ends with one or two things you'll actually do differently next game. Here's a routine that works.
Don't review a stomp. Pick a loss you don't fully understand — a close game you felt you should have won. Those hide the habits that are actually costing you rank. One game, reviewed well, beats skimming five.
Passive watching teaches nothing. Give the review a job — pick one question and answer it:
Watch at normal speed, and pause the moment something looks off.
You don't need the whole game — jump to the moments that decide it:
End every review with concrete, small fixes — not "play better". Good fixes sound like: "Ward river before pushing on cooldown," "Don't fight without summoner tracking," "Recall on 1300 gold, not 2000." One or two per game is enough to actually stick.
A second set of eyes finds what you can't. Upload the VOD to a Review room and watch it together with synced playback, voice and notes — see how to share a VOD with your coach.