Mark the enemies, #1 #2. I usually just use #1 myself and switch the marker to another enemy when the one being killed is around ~10%hp. That should give enough time to the dps to prepare switching to the next one and not shoot blindly.
Even though you are supposed to be using your enmity combo on every mob and flash regularly, marking mobs is - IMO - very important at first. Both for you and the others. It will make the kills faster and will be less hard on everyone. This way, even if you forget to combo one enemy, it will be less punishing if the players are hitting the same enemy all at once.
If by mistake, one of the enemy gets away from your flashing, it will be easier to get it back, as players won't have stacked a big enmity if they have been focusing on the marked one before.