What routes are you taking in Delta One international? I'd assume with 150-200% MQMs on those flights if they are of decent length would be netting you the first or second tier(SM & GM). And if you are going East/West in F again 150-200% MQMs I'd assume Platinum would be easy.

The last bit a mileage run to somewhere fun if you have the budget for 10K Delta One tickets would net you the rest for Diamond.

Outside of that get one of the AMEX cards that offer MQMs at certain spend levels. One of them would get you 20K total MQMs(If I remember correctly) at 50K spend. If you have 4x 10K and 8 domestics in first should easily hit that each year.