I had a broken bow eye and replaced it. (Not sure whether this thread si DSII specific in nature, mine is a DS1 and replacing the bow eye with a standard part from a boating store was easy, except for the awkward reach to the front).
For towing: I keep the trailer winch attached to the bow eye. I also loop a line from the bow eye around the winch post and back to the cleat on top of the foredeck. These go on, before I move the trailer out of the water. Wrapping the painteris mostly a way of stowing it, but it also guards against the winch pawl becoming disengaged.
I then use two ratchet straps to tie the boat to the trailer. One goes over the aft third of the cockpit, both sides connected to eyelets near the end of my trailer, I use a quite bit of padding under the strap, since I have the full height wood coamings. At this point, the boat is secured well enough for extended parking lot maneuvers.
To go on the road I always add a second ratchet strap in the front. It goes over the foredeck. It would slide off towards the front, except that I hook it under the aft end of the cleat. The ends are hooked into some convenient holes in the trailer frame. So this strap ends up pulling both down and forward.
You can't rely on the weight of the boat, because any strong bump will send it airborne and it could fly off the trailer (or shift/twist on the trailer).
Even tied down like this, I've managed to shift my boat once, by running a curb with some speed. Just a couple of inches sideways movement, but enough to let the CB jump of the roller it was resting on. It promptly dropped a few inches, making it impossible for me to shift the boat back onto the roller.
A friendly passer-by and a paddle did the trick in the end.
By using single loops of strap over the whole boat, instead of pairs of left/right straps, the boat has more of a chance to twist and to move side to side by a small amount. Just means that you need to be able to stop and inspect the rig when you hit a larger bump (like a curb).
Mast: mine rests on two crutches. One is fitted with pintles and goes where the rudder goes. The other sits in the mast step. The mast is secured primarily by a line around between the two cleats on the aft end of the cuddy and the mast. This line will hold the mast down in the forward crutch. It's wound around the mast once, and should also hold it from trying to go forward.
Back of the mast is tied to the crutch, so it can't jump off, and to the boat, so the crutch can't be pulled off. Bungees for now, but something less stretchy might be better here.
Finally, in the front, I wrap the painter around the mast, as it comes off the forward cleat. It cuts down on the swinging of the forward end of the mast, and adds a second line to resist the mast going off as a missile on a sudden stop.
This evolved from the way I took over the boat, but I'm the first to admit that I have no particular claim to having found the best system. I never tow for more than about an hour, if I went longer stretches, I might do a few things differently.