and often can equal a bad class. Check out A Geek in Korea's account.
His first mistake was staying up too late the night before a long day. In my opinion, I think this is actually the most important factor for a class going well or disaster. Being well rested, awake, and alert before you set foot in the class is so important. For me, this means going to bed at around 10:00 every night. Then, even though my first class is at 10:30 and it's only a 3 minute walk from my house, I wake up at 7:00 everyday. This gives me time for last minute prep, reviewing what I'm teaching that day so it's fresh in my head, and paperwork in my office. Also, I have time to eat breakfast and cruise the internet and update my blog, all of which help me ease into the day and be alert for class. If I go to bed any later, or wake up any later, I feel a bit stressed, which leads to stressful classes. And of course, sleepy students need a happy, awake teacher to help them wake up. A sleepy (or hungover!) teacher is just unprofessional I think.
His second mistake was playing a game where he didn't know all the rules! This has happened to me before and it's been a nightmare. Students were frustrated and I was embarrassed. So how to prevent this? NEVER make up games on the spot. NEVER! This has been the source of my bad games. You can avoid this situation in the first place by doing prep, and lots of it!
When I do prep for a class, I'll generally plan enough activities and games to fill the entire time. And then, I'll include one more optional one. This way, I'll always have enough to use the entire time and not have to make up stuff on the spot. And, I have a roster of about 30 games and activities that I'll cycle through in a semester. This is enough that I never have to do the same thing twice, but it's small enough that I understand thoroughly how to do/play all of them. I suggest that you make your own master list. Occasionally, I will incorporate news games into the list, but I'll work through all the possible questions that students might have first to make sure I am the expert in how to play.
And finally, his third mistake, which he doesn't point out himself but that I've extrapolated: he talks way too much in class. I wonder how he is able to not give the students chances to speak. Maybe he's teaching something other than conversation classes, I'm not sure. But, if he is teaching conversation classes, then I wonder how it is possible to wear your voice out. In each 1.5 hour, I talk for about 10 minutes total. The rest of the time, I'm talking individually with groups, or supervising a game or activity that the students are doing. People learn language when they are actively using it. They don't learn it passively by just listening to someone talk about it. I try to remember this as I plan my class.