Developing an Outline

To write a cohesive novel we need to make sure our story has a proper flow.  Our ideas need to mesh organically and clearly.  The best way to stay on track is to have an outline of what we want accomplished in our story.
An outline gives us an outlet to write down everything we would like to accomplish in our novel.  So first just write points you want to incorporate.  Have the main idea and then start jotting down story ideas to develop the main idea.  This looks bad now, but will make for great literature later.
We can have a great story idea in our mind but it needs to be developed through a course of events.  For us not to get confused and keep a flow in our writing we need to organize our thoughts.
Start at the top with the main idea.  The main idea is the angle we want our story conveyed so it is important we have a good understanding of what we want to accomplish.  If we are unsure of certain points we want to develop in our story, now would be a good time to do a little research.  We should have a good understanding of what we are writing about and a side bonus from research is that we may learn more points we want to include that we had not thought of.  This will add to the flavour of our novel.
Now lets look at the other points we wrote down.  How do they help in developing our main idea.  Look at your thoughts and see if they add to your story.   Imagine for a moment that you are writing a romantic novel, and there is too much information that simply confuses the reader.  Eliminate it.  If you want to include a point, you should have a clear idea of where it belongs in your story.  Obviously we don't give away too much too early in suspense fiction.  Keep a list of where to add information in your outline.
Under the main point we can now write our first supporting point, then our second, third and so on.  Under the first supporting point we can write sub points.  As we write these down keep asking yourself; Is this adding to my story?  Is it accomplishing its purpose?  Does it reflect what my main idea is?  These sub points will help develop our story and lead to the climax and conclusion.
For our sub points to have substance; do research.  If we are writing about medieval times then it would be good to research what people wore, living conditions, what they knew or didn't know.  Doing this research will add a depth to your story and help your readers feel like they are there.  Reality makes good fiction.
This process should help us keep our flow and not have any overlapping.  We can see if each supporting point is clear and needed for  the story to develop.  If it does not add to the story then discard it.  Trying to make a point fit can ruin a good novel and confuse the reader.
Looking at our supporting points again it is now time to put them in proper order.  With the research we have done we may feel one idea should come first to set the characters up properly.  When we want to introduce certain points.  Looking everything over closely will help us see how we want to line up our story.  This should then make it clear as we write and we are not jumping from idea to idea.  We want it to be cohesive, after the reader is finished they should feel a logical conclusion was developed.  It is good for them to think about your book afterwards with positive thoughts.
Of course the order will be different for a suspense novel than for science fiction; so there is no one answer for this; it is up to the author.