New Rule, thanks Ytse_Ham!
Rules:
1. Be Polite.
2. If you want people to look at your games, then use a proper chess set.
3. Include the principles/plans of the opening you played.
4. Comment on mistakes with stronger variations (sub-variations are written in blue, and variations on the blue sub-variations are written in red, these are other possible moves you could have played in the game at that time).
5. Write your intended moves into the annotations, don't just give vague ideas.
6. People know simple tactics, if one is there, you don't need to include a variation to talk about it.
7. Consider what the other side could have done differently to make it a better fight and include the variation.
8. If the opponent blunders into mate, find the best continuation and include it at the end.
9. Check the opening moves with a database and see where improvements can be made.
10. If a move is made and isn't listed in the database, check it with an engine to determine whether the move or the response was good.
11. Use an engine to help answer some of your direct questions that can't be answered any other way, but don't over-rely on it for your analysis because you won't learn that way.
12. Summarize the game's ideas. This helps you save the game into different lesson folders for review after.
13. If you did something right for the wrong reason, find out what the right reason is, and don't think like that anymore.
14. Keep fair about the game, just act like there two guys playing and you don't know them. This way you find the best play for both sides.
15. Variations and sub-variations are used to show if different moves work or don't work, so don't include blunders in them.
16. Don't spell everything out. Be concise. If there's an easy-to-see simple tactic, you don't need to talk about it. You don't need to blather about every move.
17. Even if your opponent lost, they still have lessons for you so look for them.
18. Refer to the armies not the players. Don't say, he did this, refer to it as black or white did that. (also see rules 7 and 14).
Usually during annotations and analyses, the players aren't referred to. Rather, their armies are the objects in question, i.e. "Black is better in this position because..." or "White blundered with Kxf3 as seen by..."