We always book the "Must see" excursions in advance but wait until we are on board for the "perhaps" ones.
Generally we have found the "Must see" are booked early.
Why don't you write or list some of the excursion destinations. Other folk have possibly visited with other cruiselines and may offer some advice on going alone or sticking to the itinery. My advice would be to do the more unusual places/visits because other places are easily accessed for general holidays. For example we did Barcelona for a day and we could definately spend more time there, such culture, fab. I couldn't comment on weather conditions, but they will have your money so may try and do something else rather than give back!! I don't think they would refund just for change of mind, I may be wrong!
If you've booked a world cruise I would suggest lots of homework prior to departure, don't let them drag you around all day, it can be fun on your own and I don't like to be mean but they can be very expensive, but if money's no object the world is yours. happy sailin.
I've been on many cruises including the Far East and Alaska. Usually you can book once you get on the ship as there will be several talks about the places you are going to and you may want to leave the booking of a trip untill then. However if you are going to some unsual places you may want to book in advance. If you do some cruiselines allow you to switch the trips once on the ship but others are non refundable. Read the small print. Cunard is a fantastic line to go with the Captain you'll be sailing with is great fun. Have a good time.
Ther are usualy Taxis awaiting for passengers to disembark in most ports offering very good tours at attractive prices. Please consider these options as costs fro the tours arranged by cruiselines are expensive.
You cant usually pre book excursions with Cunard ,brochure is just for information only,you book excursions onboard.There are usually talks/information on the various excursions or on one of the channels on TV.You then choose which ones you want to go o.
Book your tours beforehand (some do get full) then when you get on the ship if you decide against certain ones you can cancel up to 24 hours or so before the tour. You are not charged until yolu arrive on the ship.