Aesthetics of placement on any size medium (35mm, 6x6, 6x7, 8.10 etc.) are based on one's working interpretation of the key subject and its interrelationship with surroundings (see sample of lower-centre placement and left-corner anchor, cropped from 35mm).
The popular square (medium) format often sees centre-placement ill-considered (especially wedding photographs) as the photographer is being unconsciously constrained by the format and that a symmetrical central placement looks best, yet moving a the key object(s) away from the centre or even to the extreme edge (asymmetrical: for abstract interpretations of visual-spatial relationships) can have considerably more impact. The larger the format, the more care needs to be exercised judiciously with composition and the placement of key elements.
Very true of the other posts, but not the competition, apparently; rules can be broken and fun lessons can be learned by doing so, but you should be prepared to illumine your decision where the underlying choice is ambiguous. And that brings me to the next bit:
Look at the lighting and posing – your subjects shouldn’t be dead-center in the image, lighting should be subtle – no hot spots or blown-out highlights. And check out your enhancements – does the image look over-photoshopped? Have you lost the real meaning of the image by adding too many treatments? If so, then you shouldn’t be entering those images.
Well, goodness! Sounds like the person writing this (who also comes across as having a limited grasp of highlight/shadow control) could do with a solid grounding in foundation skills in photography rather than pander to cheap and cheerful "enhancements" per se in Photoshop. :rolleyes: