The big one is that the garage is in an easy location to reverse into and pull out - nothing worse than a 12 point turn at the end of a long day and wide enough that you can change the bearings in the garage.
If you have a t top, preferably the garage door height is sufficient that you don’t have to fold down each time. Secondly, consider making the garage ‘wet’ . Have a drain or two and tap installed in the garage meaning that you can wash the boat in the garage if you get back late and want to see what you doing without fumbling in the dark, also, means that you can run the engines in the garage without having to pull the boat out if you want to warm them up etc. and not waking up the neighbors
A stainless steel sink is handy to rinse stuff as well - might be better outside with a light to clean fish on . A few electric sockets as well if you want to have a bait freezer and battery charger.
Also consider, if you were to change boat and go bigger, would it still fit in the garage? Would be a huge pain if you had to extend another meter or the garage was too narrow.
