The most important point to remember is this. The list of things to do will never be completed. Your vessel is never 100% ready. But you have to leave some time. Do you best, very much like preparing for an exam. When its time to go, Go.
Watch the weather, but again, it will never be ideal. Be prepared to suffer a bit, don't be stupid, but you need to leave at some point.
Get into a routine quickly.
If you do suffer from occasional bouts of seasickness then take a pill well before you leave. This might be the only pill you have to take as its frequently at the start of the passage when you are most prone to seasickness ( at least in my experience).
Always think one waypoint at a time. Don't think of the whole passage, think one leg at time. Again apply common sense.
If you have warnings of imminent heavy weather, prepare a good hot meal for the crew.
Clip on. Very much like seatbelts, they are quite easy to get used to.
Reef before night fall. With lines running into the cockpit this is not so much of a problem but is definitely something to be aware of. Night is a dangerous time. Be wary.
I will add to this list when I can.