From many years of towing sailboats of all sizes but mostly trailerable boats as a former sailboat dealer may I suggest the following based on the photo.
1. Make sure you have a chain attached from trailer winch stand to bow eye but if no
chain, then tie a section of rope in the event the winch strap breaks.
2. Remove the front strap draped over the bow secured to the trailer as it can cause
damage to the boat over a period of time and place it on the back of the boat and
over the cockpit coaming to the trailer. Twist the strap a couple of times each side
to prevent slapping.
3. Go 15-20 miles and pull over to check tie downs, straps, chain and so forth. Also
check tightness of lug nuts and feel the hub. If warm that is ok but if very hot,
pull over as you have a bearing issue.
4. For long trips, I would carry a spare tire and rim along with tools and two wood
blocks for changing a tire and chocking wheels. Also include a small grease gun.
5. I do not think the motor is on the back outboard motor bracket but if it is, tie it
upward to secure in place to keep the motor from banging up and down.
6. If you have surge brakes that is great. If not, go a slower speed. Now one thing
without brakes particularly with a keel boat like yours, should the trailer start to
sway and is concerning to you, I would accelerate some to get it back under control
and then start braking slowly. Otherwise, braking might cause loss of control.
7. On the trailer, make sure safety chains are crossed and if too long, twist them to
shorten up and put the hooks in backwards so hitting a bump will not allow them to
come off.
I quit counting after two million miles.