Be sure you leave plenty of time between your flight arrival and the ship's check-in time. By the time you land, get baggage, wait on the transfer to be loaded and travel time (up to 2 hours) you've used up a big portion of the day.
Planning is everything with a one way Alaska sailing. You can check with CCL or your T/A to get recommended flight arival times. I alwats a 1 hour to the recommendation, you never know.