To make a good thread, you need to think of your subject, and what is going to be in side your thread.
Using correct capitals letters, spelling, and grammar makes your thread look a little more professional, and will get more views.
A lot of people get annoyed at threads that have incorrect spelling, and capitals. And having too many exclamation marks at the end of a sentence gets annoying too. Remember that you can only post a certain amount of characters, and you don't want to waste those characters on exclamation marks, maybe one or two is fine. This means don't do this:
"OMG I AM IN CAPITALS!!!!!!!!!!!!!!!!!!!".
One that will result in a warning, for spam, because it is pointless, and two it has too many exclamation marks.
Something else that is annoying, is people posting everything in capitals. And using abreviations gets annoying as well, because it takes twice as long to read.
Which would take longer:
"Are you using visual c++, or are you using normal c++?"
"RU USIN VISUAL C++ OR RU USING NORMALZ?"

The one that has correct grammar, spelling, and capitals is quicker, because with the abreviated one, you have to figure out what each of the characters mean before you can actually read it.

Hope this has helped!