Writing in Chinese - What rules are there for handwriting vs printed I've recently found out that I've been incorrectly writing a lot of Chinese characters

Examples:


  口日目


I've been writing them with the little feet (not sure of a better name for them) but have been told that they are written without them. Other examples would be:


  了字好


As I've been writing the line from from the centre to the bottom straight but have been told it needs to be curved. 

Looking at @congliu's answer to another question the above holds true but that was regarding a different topic and didn't cover this topic



Excluding speed writing and calligraphy how would you know what to write(By hand) based off printed text?
黑体 is the font you are using and talking about, it is usually set as default Simplified Chinese font, but 楷体 or 楷书 is the font that more similar to the handwriting Chinese, if you want to learn handwriting from printing Chinese, you'd better download this font, you may need some books that teach you how to write every stroke and their order, every Chinese kid learn this before trying to write the first character.

The little feet are always there, you should write like this, it is part of this character not just "serifs" for beauty. The two feet are different in the bottom, the left foot is a longer 竖（the straight line）, the right foot is called 竖钩, you must write a little angle to left after the straight line, if the angle is to right it will be called 竖提, the last stroke is the bottom bar(横), connect the left straight line（竖）and the line with angle（竖钩）with the little bar(横), importantly, don't start from the end of the left line(竖), leave a little foot there.

The curve in 了字好 is also important, you may see the curve in 楷体 font.

If you want to learn more about strokes I suggest you read this in Wikipedia: http://en.wikipedia.org/wiki/Stroke_(CJKV_character)