YMMV, but I am of the firm view we are not in normal times.
I have not sailed with Celebrity, but several of the major middle market (Princess, Royal, Holland America, Avalon, P&O) cruise lines (i.e. not upper market smaller ships like Azamara or Silversea and the like)
Pre covid there were sites where you wing it and could pick up last minute cruise deals for a song. Not now and probably not not for the next 24 months or so, there is so much pent up demand.
When I was short of cash I bought an obstructed view cabin with a window. I would go mental in a room with no window for 14 days/nights. Just in case we have rough seas, I now always book a mid ship balcony that results in the minimum movement (think about a seesaw, there is almost no movement in the middle and great movement on the extremities (like at the aft of the ship). Plenty of fresh air (particularly in covid times), a good view and a place to relax from other people. Could never justify the price of a suite after looking at the options many times.
I have never paid for a drinks package, could never make the figures stand up. I payg and the settlement bill at the end of the cruise has always been way lower than the package.
I have never paid for a "specialty" restaurant, the normal free ones are fine and friends who forked out for the privilege of the paid ones have told me never again, it wasn't that much better other than an improved staff/diner ratio.
90% of the time I book my own shore excursions for approx 50% of what the cruise line charges and the tours are better in my opinion. Just think 6-10 people in a mini bus with a local versus herding 50+ people on and off of a large bus that can only go on certain roads and the lost time at every stop with all those people getting on and off and the people with walkers and ailments etc and they only go where the cruise line gets a big kickback. However - *danger danger* make sure you get a good reputable operator and understand the risks if you are late back to the ship. I joined cruise critic site and team up with others to book tours and absorb the recommendations of people who have been there and done that at each port, some of them many times.
I do like the internet packages on some cruise lines and not others. Also depends on the cruise. If it is port intensive (you are in a port with largish cities nearly every day, use the free wifi at the port or in coffee shops or even some tour buses. However if your cruise has a large proportion of sea days or you are sailing between semi uninhabited islands and you like to be in regular contact, then buy an internet package large enough to suit your online time.
Gratuities depend on the cruise line. Some operating out of Australia include the gratuities as part of the fare and the staff get reasonable wages. If gratuities are not included, you can be sure the staff on board are being paid very poorly and be prepared to tip them for their service - particularly the cabin service staff who work huge hours and work very hard with some very demanding passengers.
I usually book direct through the cruise line, but sometimes through an agent - especially when they run expos and offer special deals.
Already booked two cruises (May, Oct 23) and considering where I want to go in 2024.