I don’t think there’s any evidence that ratios are important. Rather it is amounts.
Get good amounts of EHA and DHA. For example 2 grams of DHA and 800 mg of EPA. Getting more than this is OK also.
If you are older, GLA is good also, about 250 mg. The relatively young probably have no use for it, as the need comes as levels of the enzyme required to produce it drop with age. I can’t define any specific age as a cut-off: consider it a grey-scale sort of thing. But for example if you are in your 20’s I doubt that supplementing with this will do anything, in most cases anyway.
Get a good amount of oleic acid, for example from olive oil. A couple of ounces a day is good. An ounce per day would be better than nothing.
It’s also nice to get some coconut oil – not hydrogenated coconut oil, but the natural thing, for example extra virgin coconut oil. Again, an ounce or two per day is good. However, it’s not as if you can’t do well without it. Using it may speed metabolism a little and improve the skin, if there’s room for improvement.
While not necessary if doing the above, nuts are also a fine source of oils.
If the rest of your diet is in order, total calories are appropriate, etc, saturated fats are not a problem.
Trans fats are to be avoided.
If we did not live in the society and environment we do then it might be desirable to also look out to get linoleic acid (an omega-6) as it is an essential fatty acid and in low concentration in most foods. However we live in a society and environment where oils man would not naturally consume much of – for example, corn, soy, and safflower – are ubiquitous.
The chances are your body is already vastly overloaded with linoleic acid, and cannot lose it slowly. So you don’t need to look to get it: rather look to minimize consumption of the above oils and of foods prepared with them. (However, high-oleic corn and high-oleic safflower are perfectly acceptable and healthy.)
Avoid trans fats.