Keep It Sharp
Not surprisingly, the single biggest factor governing how well a router plane handles is the sharpness of the blade. A dull blade digs in and refuses to cut. And it always seems to dig really deep right when the front of the plane goes off the end of the board. I’ve often thought, "Well, it's just a short job. I'll struggle through and sharpen it later." But this way of doing things invariably makes a short job into a long one.
Waxing the base of the plane makes almost as much difference as sharpening the blade. I don't know how many woodworkers routinely wax their planes, but I suspect that if you try it once, you'll never look back. According to my rough measurements, the coefficient of kinetic friction of an unwaxed plane on dry wood is about 0.2. If you wax the bottom, this number becomes approximately 0.1. I suspect that the latter number is even lower when the plane is moving briskly across the wood due to an effect similar to ice melting underneath skate blades. This translates into the plane being easier to push and a lot less work to use.
Making Mechanics Work for You
If you use a router plane incorrectly, it’s all too easy to end up fighting yourself. I prefer to push the router plane. This is because if I pull, I have to exert two opposing forces; the first one pulls the plane along the board toward me but also tends to lift it up out of the cut. I then have to exert an opposing force to push it down. In practice this equates to being hunched over the job and ending the day with a needlessly tired back and aching arms.
Another way to make mechanics work for you is to keep the fence between you and the wood. As you push the plane along the board, not only are you pushing it down but you are automatically holding the fence against the wood as well.
You don’t need to exert yourself as much if you push rather than pull your router plane.