The video where I judiciously use clips from anime, Mad Men, and Chumbawamba.
0:00 Intro
1:39 Starting at Level 3
4:17 Forgetting your 4 boosts
5:18 Not maxing out key stats
8:40 Assuming things with similar names are the same
9:46 Assuming ability scores are the same
11:11 Concentrate isn't concentration
12:20 Some actions aren't "free" here
14:39 Attacking 3 times (standing in place)
16:41 Thinking as individuals
18:00 Thinking only about damage
21:38 Thinking spells will "win"
24:54 Saving healing for knockouts
26:36 Not recovering between combats
27:53 Overwhelming players
29:09 Ignoring the encounter building guidelines
32:30 Ignoring/changing core rules
34:22 Restricting yourself to the rules
35:54 Not giving out essential treasures