There were some people last night wanting to learn more about how to look at logs.
Here are two great sources I found to help you analyze the logs that are being posted to help you figure out how to improve.
First, a thread on icy-veins by a big-time warlock theory crafter and mythic raider whom I really trust.
Next, a twitch broadcaster and mythic raider (and old school raider with a corrupted Ashbringer!) who did a live video on how to look at logs. Note: these are pretty long and he was answering questions when he did it. First video is about 1.5 hours and second is 1 hour.
Part One (Skip to about 18 min in)