Here is the thing about this thread. There are a lot of folks who don't like that their fuel economy is cut in half or more when they pull their trailers. For those who only use their trailers for short caping excursions, whatever they do to improve aerodynamics is not going to gain them much in the form of payback through fuel savings. But, those who do haul long distances a couple of time a year, should see significant savings in fuel, if they improve their aerodynamics. Sorry, a wax job does virtually nothing, and what it does help improve is so insignificant it's only worth doing to make your rig look nice. Neither is smoothing out the seams with a caulking gun.
Everyone I have ever talked to uses the airstream as a benchmark for the ultimate in towing and efficiency, why? because of it's shape. In order to come close to that (If) your trailer is relatively flat, there are a few things an owner can do to improve the towability and improve fuel savings at the pump.
Realize that a flat front is essentially a parachute you are pulling along at 60 mph. hit a hill and watch your truck react. Not only does it have to contend with the hill, and the actual weight of your trailer, that parachute is still acting upon your tow vehicle as you climb. Horsepower can take care of the trailer weight, but aerodynamic improvements will help eliminate that parachute and the drag it creates.
For owners with a pickup as a tow vehicle, you have a couple of choices, add a cap over the bed and reduce the height difference between your truck and the campers roofline and also reduce the "gap" between which helps reduce turbulance and overall drag. If you add a wing to the rear of your cap, even better, move the air over the top of your trailer essentially punching a hole in the air. If you don't want the cap solution, or you have a lower roofline vehicle like an SUV or a Sedan car, your choices to improve aerodynamics is somewhat limited. The only real solution is to look at making your trailer more "wind friendly" - mimic the Airstreams lines as much as possible.
The nose cone essentially does this, yes there is a cost, but so is a truck cap, either way there is a cost involved. Or trade in your square tailer for one of those new factory rounded front trailers on the market today.
Hmmmm... wonder where the manufacturers got the brilliant idea to round the front of their new models. Probably has a lot to do with towability and fuel economy, but thats just a guess.
I want owners to know that there are options to improve fuel savings, and yes there is a cost to get there, but the way I see it, either you pay the manufacturer to improve aerodynamics and it is reflected in the retail price or you find other solution as suggested in this thread, but there is a cost - either way. I know how angry I was the first time I took a trip with our camper. I was not impressed to have to double my expected fuel budget for that trip.
Do what works best for you. If you are happy with your fuel economy, great - have a wonderful life, if not, you can do something about it.