Pretty obvious point here but, important to stress it. Do not forget the ring! Write a not to yourself, have a friend remind you, have it set aside where you won’t forget it, do whatever it takes to not forget it on the big day. You will likely be nervous that day so something like that could slip your mind, so do what you need to so you don’t forget to bring in for the big question.
That goes for everything. Do what works for you, to remind yourself of the plans you have made. Write a list to keep everything organized and in line so you don’t forget to do a special thing you have planned. Keep this list hidden though of course cause that’s obviously a dead giveaway. If you have a lots of little things consider writing them down so when the time comes nothing is missed. You don’t need to carry the list with you per say, but have a list written or mental list to help things go as planned.
If all else fails and you do forget the ring, don’t give up, improvise. That goes for anything that day. If it’s forgotten or doesn’t go as planned the. Improvise, it may even turn out better than you planned.