My spouse and I don’t have a lot of flexibility when it comes to travel dates, so it’s not too often we come across a stellar deal using miles. Our strategy has been that we shift as much of our spend as possible to our DL Amex cards and rack up miles so that every couple of years we each have enough for a RT D1 Award to Asia or Europe. In the meantime we refrain from redeeming the miles unless there’s a good deal too good to pass up.

Edited to add: I see several posts where people are suggesting good deals on partners using DL miles for travel outside the US. By all means if it’s a good deal, go for it, but be aware of the risk involved with using DL miles on a Partner Operated flight. If the flight is far in the future, there is a strong possibility of a schedule change and the “new” flight on the partner would require award inventory with a higher amount of miles than you initially purchased with. If this was a DL Metal flight, DL could force open award inventory at the original rate and keep things as an even exchange. With a partner, there’s no guarantee they would do this. For that reason, I never redeem skymiles on non-DL operated/marketed flights.