As I approach a boat at anchor
or at a dock
I always check to see the mast
is straight and see if the rigging
looks in good condition. See if she sits on her lines in the water
. If you are launching off a trailer then certainly make sure stays and shrouds are all attached and that cotter pins are secure and can't fall out before launching. Thruhulls should be closed. Docklines are ready and the boat can't drift away.
Once in the water
, I check tiller to rudder
play to make certain there isn't any and see that the tiller can be raised and lowered at the cockpit
end. Check your halyards when raising the sails
to make certain there isn't any fouling and they raise and lower the sails
easily. Once the sails are raised then do some tacks and jibs and make certain the boat tracks properly when the tiller is centered.
There is much more but you get the idea.
Have a great sail!!