personally i would have to say a good DM style of playing (with scout class) would be this:
Start with this setup:
Setup #1:Left: Sprint
Up: Stimpack
Right: Invisible
Down: Smoke
Step #1 When you get to a group of enemies use invisible. Then switch it out for flash.
Your setup will look like this:
Setup #2:Left: Sprint
Up: Stimpack
Right: Flash
Down: Smoke
Step #2 Use flash first and then smoke on the enemies.
Step #3 Use stimpack and then another smoke followed shortly afterward by another flash.
Step #4 Switch back to Setup #1 and go invisible.
Step #5 While invisible switch out Up Right and Down for strength, defense, and accuracy trinkets of the highest grade.
Step #6 When you die switch back to Setup #1 and repeat steps.
Hope this helps
Note:The Sprint staying on the left side is because if you get caught in someone else's smoke, you should get out of it.
Doing that helps you get a better kill to death ratio.