If I've learned anything over the years, it's that I have so SO much more to learn. There will always be another trick, another hack and somewhere new that will pop up luring us away from home.
But over the years, we've tried to apply a few hard learnt lessons to our future fun.
Never trust the 'oh, that'll be ok' thought whilst booking
It will most certainly not be. Getting up at 3am for a 6am flight is not a good start to the day (even when you're off to Morocco), the booked "reliable" cabbie will probably not turn up *cough* Vienna *cough* until it's almost too late and staying at the far reaches of a town with little to no public transport will break holiday spirit or be expensive as you line local taxi drivers pockets - here's looking at you Dublin.
Take time to rest
I almost always exhaust us. Forgetting that we are supposed to be getting R&R time on "holiday", even the definition "an extended period of leisure and recreation, especially one spent away from home or in travelling" indicates some rest, so fighting my need to see everywhere now we have started to embrace the old slow travel ethos - taking 3 days to explore a city that could be 'done' in an afternoon like Lille and properly taking time to sleep-in, booking a good spa and retreating away from the demands of the world.
Prepare for the worst-case scenario
Overthinking is one of my personality, er, quirks. There I said it. Admitted it to the world. Luckily there is a filter that helps me appear as a normal functioning human being, but when it comes to travelling being able to overplan helps. I'm the one with blister plasters at the wedding, I always have print copies of the hotel address for when my phone battery dies and thanks to overpacking my carry-on, could wash my own clothes and shampoo my hair with my own products when our suitcases were in the wrong country.
Travel off-peak & check the general weather
There is nothing worse than queuing for hour upon hour upon hour to finally glimpse Mona Lisa's enigmatic smile in the paint (only to, er, realise that your camera battery died), to shuffle through the Sistine Chapel or for 2 hours in Florida sunshine (even though it was the most entertaining queue ever) as we waited for our turn at the Wizarding World of Harry Potter. Also related, even though weather is as unpredictable as London transport delay excuses, why book a holiday in a country where the daily heat tops out at 40°C? Not for me thanks. Autumn often seems to be a nice, settled season in most countries.
Never book the activity/thing you want to do the most on the last day
It was a 10-year olds tears in New Zealand that taught me this one. Her family had saved swimming with wild dolphins for the last day of their holiday before going home to Germany, and sadly because of storms the weather was just too bad for the boat to go out. I luckily was staying longer and simply took myself to cute cafe to read my book, but her heart was broken - and seriously mine for her.