Here's mine:
1. Try to get room-only discounts for your time of travel. It's not always possible but it helps.
2. Buy the Canadian Resident park tickets if you can.
3. Carefully evaluate if the
DDP is for you. We pay less without it. And "free dining" is not free.
4. Limit your sit-down meals and limit alcohol at restaurant/park prices. Not only is it expensive but there are mandatory tips at TS restaurants that add up really fast.
5. Split meals if you're not a big eater. DW and I split the Breakfast Cuban at Spyglass (CBR) Grill for breakfast as well as a number of items at Flametree BBQ (AK). This can be done at lots of CS locations. WDW portions are usually on the large side.
6. Limit using a CC while there to avoid the dreaded "foreign exchange fees".
6a. Put away a little each month in a US$ savings account to mitigate the shifting exchange rate over time, or...
6b. Consider taking a bunch of Disney gift cards to pay down expenses as you put them on your Magic Band. Avoids the forex fees but you're stuck with the exchange rate on the day you use them.
7. Use a credit card that has cash back or points (or whatever you will benefit most from) that has comprehensive travel benefits so you don't have to buy flight/vacation insurance from third parties.
8. What everyone else said above.