..agreed with that - you know the lines are connected correctly - they're just tangled in the middle. It can take a bit of time, but the more you do it, the easier it gets.
I check the brake line before anything else, then, as you mention, go from the A's and work through them.
Of course, best action is to try and prevent the tangles in the first place, so if you have a riser bag, would always recommend using that.
I was forever getting my lines tangled when I started and it took a while to sort. However, I rarely get tangles now, and when I do, they can usually be sorted quickly.
Best of luck!