It's a good question.
When you think about it, if your n-3/n-6 ratio is close to 1:1 - 1:2 with calories coming from PUFA's being less than 5% it is probably a good marker that you have your diet dialed in really well.
The systemic inflammation that a high n-3/n-6 ratio causes is definitely a key factor in most 'diseases of civilization'.
I need to go and stew on my next comment to be really sure, but I think it would be fair to say that the process of getting your n-3/n-6 ratio to 1:1 - 1:2 would optimise most of your diet - the only thing left lingering in my mind is sugar consumption.
Personally, to bring my n-6 consumption down as much as possible I have stopped regularly eating chicken, buy mostly (90%) pasture fed ruminants instead, if I eat nuts I eat macadamias due to there high saturated fat content and I'm really anal about having anything processed, because it usually contains a lot of vegetable franken oils.