By the time I decided to finish DM. I had all my AR and SMG already diamond. As it was an early short goal. It was after I joined CAG that I thought I should step it up...I just went with the flow as I had been playing with the clan most the time. When I was solo, I'd work non stop Goin in games just to kill as many people. Win or lose, it was a matter of how many kills I could stack up and get to the 5 challenges. Then it became a strategic matter, trying to continue the same pattern and finish the 5 streaks, long, and dubs. Mostly holding a spot to finish the 5 quickest. Basically just know your goal as you begin to spam games if your solo. If your rolling with the clan, put one of your best guns in a class and the rest all that need to be diamond. So you can best support the team and work on diamond too. I went shotties, and snipers at first. Then my pistols and lastly the lmgs. Then the knife. Which probably should be done on small maps. I completed mine on a nuke town weekend night. 200 kills, and then the challenges. Good luck. Just remember it isn't about winning or losing as you solo.