I never dip my trailer, and if I actually put my trailer on the beach, digging might be an option, but it still looks like more work than just dragging the boat on and off the trailer. Instead to help get it on and off easily, I put silicon onto my bunks when the boat is off of it. Seems to work for about six months, then it needs a refresh. The winch then pulls the boat right up onto the trailer. For even easier retrieval, I have a remote controlled electric winch project I need to finish. I also rounded the ends of the bunks over into a nice half round to again help ease it on, and off.
In order to fold the wheels down I have to slide the boat back .5 meter. Same with putting it back on the trailer. The bow does have to go really high to get it onto the trailer though. On flat ground I can easily do it myself.