When Should You Start A New Paragraph?

Answer 1

When the idea of the existing paragraph has reached it's logical conclusion and it's time to move onto the next idea.

Answer 2

That mostly depends on what you're writing about.
The general rule is, start a new paragraphy when you start developing a new idea. If you're writing an essay, you should be able to logically point each paragraph back to your main thesis. If you're writing narrative, well, you probably don't have a thesis, but you should start a new paragraph whenever someone new is speaking, whenever a character has a new thought, or whenever significantly new action occurs.
This is, of course, a very rough estimation. Without knowing your writing style or what you're trying to accomplish, it's really difficult to try to give better advise than this.

Answer 3

When the paragraph you've been writing has already served its purpose. Also each different character's dialogue must have a different paragraph.

Answer 4

when the subject changes but if its too long and all about one thing, you can enter it, but don't indent it it's a continuance but it doesn't seem so longwinded