Sure, You can do all the research you want about preferred routes. Even file for it. It is a good exercise.
But It is unlikely you will get what you ask for. But it is a very good habit to get into. And who knows Maybe you will actaull get the magic route!!
Imagine your route from Washington DC to Miami you file Washington, Nashville, Miami, you get that… then once airborn, you are over Virginia, and the controller says N12345 Cleared Direct Orlando, then as filed….
D’oH!!!
ATC will do everything in their power to get you out of their hair asap!! Shorter routes mean less time for them to worry about you… and less workload for the controller.
Here is what I do…
If I Filed N40 to IAD
Would look like this…
IFR-N501JC Type:C500/G 310Kts Dep: KN40
Dept: 1900Z 14,000 FILED ROUTE : DIRECT
Dest: KIAD ETE: 0:44
FOB: 0500 Altn: MDG SOB: 2 Color: W/G
.
I am not sure what you use, But I use craft when I get my clearance. I use white cards, 5X8inch
Holding it long ways this is how I do it.
C (cleared) to IAD
R (route) LANNA J48 EMI
A (altitude) 2000 exp 8000 +5m
F (frequency departure) 124.45
T (transponder) 5454
Depending on the wind and the runway at IAD, they may give me any number of routes..