「manner」と「manners」の違いは何?

Someone advised me the other day:

Nick, you always put the chopsticks on top of your bowl before you take a picture.
× That's not a good manner.
○ That's not good manners.

When you mean "the way something is done", use "manner". However, when you mean something like "etiquette", use "manners".

• (definitions from Edict)
• 風 (ふう) (adj-na,n,n-suf) (1) method; manner; way; style; (2) appearance; air; (3) tendency;
• 方法 (ほうほう) (n) method; process; manner; way; means; technique; (P);
• 作法 (さほう) (n) manners; etiquette; propriety; (P);
• 習慣 (しゅうかん) (n,adj-no) custom; habit; manners; (P);

This person was talking about the manner in which I place my chopsticks. Take a look at today's photo. I'm using a chopstick rest for the chopsticks.

• 箸置 (はしおき) (n) chopstick rest;

Compare that to a recent photo of my noodles:

http://upgradeenglish.blogspot.com/2010/01/appeal.html

Do you approve of my manners now?

The other thing to notice in today's photo is that it's not noodles! Maybe you thought I only cook noodles, but it's not true! The menu for tonight's meal was fried brown rice, which was flavored with garam masala and Sri Lankan pickles. I ate that with dried tofu and cilantro, plus a bowl of spinach, onion, and garlic soup.

As a foreigner here, it's easy to have bad manners sometimes. If you catch me doing something in a manner which I should not, let me know!