Heres what I did for our upcoming Poly/BC split stay (4 nights at each).
1. Made reservations at our first resort (Poly) more than 180 days out (we needed two rooms, one for us and one for my parents).
2. At 180 days out, made all of our ADRs (for us and my parents) for the entire trip (at both resorts).
3. Waited patiently for room discounts (this, by the way, was the hardest part

).
4. When room discounts finally came out, I applied them to our existing Poly reservations and then added new reservations at the Beach Club with the same discount (in our case, with two rooms needed at each resort, AP discounts were the better deal because the 5% difference between the AP and GP discounts was greater than the cost of upgrading one of us to an AP). All reservations, at this point, were ticketless and Magical Express was added to the front end of the Poly reservations and to the back end of the BC ressies.
5. Paid off the reservations using a Disney Visa rewards card.
6. Bought discounted MYW tickets at
Undercover Tourist (also using Disney Visa rewards card).
7. Upon arrival at WDW, I will first price bridge my discounted MWY ticket by using it to go through a turn style at a park (to get credit for the current gate price) then, at Guest Relations, using mostly Disney Visa rewards points, Ill upgrade that ticket to an AP (between the Undercover Tourist discounts and use of Disney Visa rewards points, the upgrade of my MWY ticket to an AP is basically free).
8. While at Poly, we plan to have a rest/
MVMCP day, 2 MK days, and then go to EP on our resort transfer day (i.e., check out of Poly, hop onto EP Monorail, enjoy EP, and then check into BC that afternoon). While at BC, we plan to have a HS day, an AK day, and a second EP day. We plan to have bell services transport our luggage between resorts.