After a number of requests I have put together a quick tutorial on creating structural openings in walls using customised door and window families. YouTube link below:
In many of the Revit Structure training manuals, a structural opening is often placed using the Wall Opening tool on the Home-Opening Panel as shown below.
This will produce an opening but will not automatically detail this in an elevation and section view with a symbolic opening symbol. I also find this type of opening a little difficult to control within the model once it is placed. An alternative to this method is to create wall openings using Doors and Windows. These tools are found on the Architect and Site Ribbon as shown below.
The door and window tools will create a basic structural openings through a wall and create the symbolic details required. Doors and Windows can be placed in plan views or sections and elevations if required. I often find a window opening very useful for creating high level openings for services by using the sill height tool in the properties window.
The main disadvantage with Door and Window openings is that the Width and Height parameters are Type driven which means that you will need to create a duplicate type for each new size which can get rather time consuming.
An alternative to this is to convert the type parameters to instance parameters within the family file. This will then create a nice and easy tool for structural Wall openings. See the youTube tutorial.
Hope this helps,