I'd encourage trying to keep with OOTB Display Reps where possible unless you are really experienced with changing them because you can make a mess pretty quickly and make things hard for yourself. It's not called a matrix for nothing. It also makes upgrading easier.
This is how I would read the OOTB Display Representations.
Standard - Whatever? it's too generic for me to use for anything.
Low Detail - Site plans large scale plans,schematic drawings
Medium Detail - Working drawings 1:100
High Detail - Detailing, Room layouts
Presentation - Design Drawings.
Reflected - Electrical & service drawings.
Screened - Similar to Reflected- use as backgrounds (I don't).
I would make adjustments to many objects to get extra graphics. So the more display reps you have, the more overrides or adjustments you have to make to get each different view looking correct so Keep It Simple. But as James showed in the last post, sometimes adding another DR can give you needed flexibility.
It's a little tricky getting your head around the fact that these are plan views and it mixes up a little when you move to model views, Switch to Presentation Display Rep and an isometric view. Now click on a wall to edit style and look at the Display Properties tab. The bold type indicates that it's the Model High Detail view that is linked to the presentation view (OOTB) when in ISO (Or perspective) mode. mmmmm....... I will try to come back and add some links to great detailed articles on the Display Rep System.
Tip: For presentation & design sketches, your wall default could have only the shrinkwrap display on including the hatch. Create a 'Shrinkwrap Wall' aecMaterial and set (all) your wall default style to use this material for the shrinkwrap. As all your componants are off, the drawing now displays a generic hatch patten (could be solid fill or 45d lines, 50% saturation) whatever is set in ShrinkWrapWall) for ALL walls. Cavities are not shown. Working this way allows you to have NO overrides set in each wall style itself which will by default have all componants to be displayed ByMaterial.