Interesting topic. If we get the right discussion going, we will see how different - with different goals - people use IF.
I don’t fly real world routes, so real-world flight plans I don’t bother with. My flight plan always includes the destination and departure airport. This may sound obvious, but you’ll be blown away by how many pilots end their flight plan on a fix near an airport somewhere.
Departure flight plan
If the fixes are available, I will always make a complete straight out departure, right to the end of the cone. My next waypoint is placed so that I don’t have to make a sharp turn to anywhere, with the risk in clashing in my parallel takeoff.
Arrival flight plan
Near my arrival airport, I include a fix 100 NM out and another one 50 NM out. These are two important waypoints in the flight plan. It’s where I will be descending. If I want I can use the flight assistant app to automatically start my descent, so that when I reach 50 NM out I will be at 16-18,000 feet. By the time I get there, I check the airport’s ATIS, determine the runway, and add some fixes to my fligtplan that bring me near the runway. I do this in such a way, that I will be coming in via a downwind leg.
When there’s enough fixes available, I set my fixes all the way into the ILS cone.
On-route flight plan
After I create my departure flightplan and I have set the fix 100 NM out of my departure airport, I get a straight line between these points. I then scan the route of this straight line, and when I see a few airports along this route, I include them into my flight plan.
So there you go. How to setup a happy real-non-world flight plan :-)