Assuming (as I think your question implies) that you want to write anything other than free verse and assuming our judges know how to evaluate poetry (no offense to any judges, but you are anonymous and rotate, and I just don’t know anything about all ya’ll’s background with poetry), I can give you some profound but probably hard to implement advice from Paul Fussell, the author of Poetic Meter and Poetic Form. It is certainly advice that has challenged me. It comes down to the fact that we have to move beyond writing “by ear” (to use your excellent term) and THEN move beyond writing overly strict meter. Fussell writes:
We can discriminate three degrees of metrical competence in poets. In the lowest degree, exemplified by the effusions which appear in rural newspapers, we feel a metrical imperative either not at all or
only very rarely . . .
. . . .
Here so much effort is going into finding rhymes that little energy is left over for the meter.
In the middle range of metrical competence we find poems which establish in the first line a rigorously regular metric and then adhere religiously to it with little or no variation. . . . Swinburne said of [one such poem]: “Verse assuredly it is not; there can be no verse where there is no modulation.” . . . .
In poems of the third and most sophisticated metrical kind, the entire function of mere is very different from what it is in the second sort. Emerson’s remark helps suggest the all-important difference: “It is not meters, but a meter-making argument that makes a poem.” Or as Pound puts it, “[Meter] can’t be merely a careless dash off, with no grip and no real hold to the words and sense.” In this kind of poem the poet establishes regularity only to depart from it expressively. When he does compose a metrically regular line it is not because the metrical scheme tells him to, but because something in the matter he is embodying impels him toward a momentary regularity. . . .
“Most arts,” writes Pound, “attain their effect by using a fixed element and a variable.” The fixed element in poetry is the received or contrived grid or framework of metrical regularity; the variable is the action of the rhythm of the language as it departs from this framework.
(N.B.: the first alteration is mine; the second is Fussell’s.)
At bottom, we need to scan our poetry and learn the effects of replacing the regular foot with a substitution. I believe that the general effects of most substitutions can be LEARNED, but some of THIS can possibly be done by ear.
And of course, this is just one issue, but a key one. There are issues of word choice, metaphors, allusions, rhyme scheme (including use of fixed forms), figures, etc.
Does this help at all?