Umm not to be rude but don't use DF. When you use DF you shuffle the deck and accept that whatever comes your way is what you get.

If you want a kill either ask your FC, join a linkshell, join a PF group (either single kill or farm) or create your own PF group. Last night on Odin (EU) there were sometimes 3 PF groups at once all going for garuda and another 3 for Titan, only 1 for Ifrit.

The only time I would use DF is at 3am when there are very few people on and even that takes ages better to log off and go to bed.

In conclusion the only suggestion I have is a big pat on the back for SE for implementing the PF.