I use a similar one (13-050_, and I find the technique that works for me is to keep the depth of cut very shallow to start off with, and to do the majority of the work with the hand on the fence, and use the hand on the handle to keep it upright. As you get deeper you can start to put a bit more force on the hand on the handle, as the plane is now running in the groove, with less reliance on the fence.
Not sure if the photo has the blade and fence far apart to show some detail, but I would be having the fence close to the cutter, it reduces any twist and lets you drive the plane more effectively.
In terms of workholding, the suggestions for small temporary attachments are how I would approach it. maybe with the help of a cantilever clamp or a sticking board type set up.
The thing I don't like about this type of plane is setting up the fence when you want to change orientation. I modified a wooden rebate plane to a plough plane. It had a 6mm tang on an 18mm blade. I turned the blade over, sharpened the tang, took 6mm off either side of the body to a depth of 6mm, drilled a couple of holes in the body for a simple fence. Granted, I use a 6mm deep 6mm wide groove that is 6mm up from the bottom of the work piece as a sort of standard, but it works for me and the things I make with that plane. Plus it only cost me a tenner, needs no set up before working, and I can swap the fence to either side and it is always at the same distance from the blade.