Believe it or not, Diana's skill sequence really does matter. You must ALWAYS start her W when you are going into the jungle. The ONLY exception is if you are going for a level 1 invade or gank. In those cases, you will start your E and initiate with Flash into your E. Diana's Q is her hardest ability because it is her skill shot. The thing you need to realize about her skill shot is that it doesn't go in a straight line, so you have to time and position it just correctly to hit your enemy with it, due to the curve it has. 90% of the time, when you want to kill someone, you will land your Q, activate your W, use your R, use your E, use your Q again (if it is off of cooldown) and finish them off with R. One of the mechanics that a lot of people are confused about with Diana is that, when she is using her R, there is a small timeframe in which she becomes untargetable. Use this to your advantage when you're in 1 on 1 with a skill shot champion such as Ezreal or a ground-target burst champion like Syndra. Another way to take advantage of it is dodging a Karthus R.