A near occasion for mortal sin is basically something etc which due to its nature or due for for the person in particular – it generally or always (or would likely) – leads one to commit the mortal sin in question.
So for example if one usually would fall into the mortal sin of getting drunk- loosing ones reason when one goes to a particular place – that place or the situation there can be said to be a near occasion.
As for scruples - put sure to have a “regular confessor” who can judge regarding such and knowing your difficulties can direct one --such is the age old practice.
As for looks…
Jimmy Akin of Catholic Answers:
jimmyakin.com/2009/01/appreciating-beauty-vs-concupiscence.html
One needs of course too a “reasonable”
custodia occulorum (custody of the eyes)
(particularily in the case of those who are dressed rather immodestly)
And the virtue of modesty protects chastity.
Catechism:
2520 Baptism confers on its recipient the grace of purification from all sins. But the baptized must continue to struggle against concupiscence of the flesh and disordered desires. With God’s grace he will prevail
- by the virtue and gift of chastity, for chastity lets us love with upright and undivided heart;
- by purity of intention which consists in seeking the true end of man: with simplicity of vision, the baptized person seeks to find and to fulfill God’s will in everything;313
- by purity of vision, external and internal; by discipline of feelings and imagination; by refusing all complicity in impure thoughts that incline us to turn aside from the path of God’s commandments: “Appearance arouses yearning in fools”;314
- by prayer:
I thought that continence arose from one’s own powers, which I did not recognize in myself. I was foolish enough not to know . . . that no one can be continent unless you grant it. For you would surely have granted it if my inner groaning had reached your ears and I with firm faith had cast my cares on you.315
2521 Purity requires modesty, an integral part of temperance. Modesty protects the intimate center of the person. It means refusing to unveil what should remain hidden. It is ordered to chastity to whose sensitivity it bears witness. It guides how one looks at others and behaves toward them in conformity with the dignity of persons and their solidarity.
2522 Modesty protects the mystery of persons and their love. It encourages patience and moderation in loving relationships; it requires that the conditions for the definitive giving and commitment of man and woman to one another be fulfilled. Modesty is decency. It inspires one’s choice of clothing. It keeps silence or reserve where there is evident risk of unhealthy curiosity. It is discreet.
2523 There is a modesty of the feelings as well as of the body. It protests, for example, against the voyeuristic explorations of the human body in certain advertisements, or against the solicitations of certain media that go too far in the exhibition of intimate things. Modesty inspires a way of life which makes it possible to resist the allurements of fashion and the pressures of prevailing ideologies.
2524 The forms taken by modesty vary from one culture to another. Everywhere, however, modesty exists as an intuition of the spiritual dignity proper to man. It is born with the awakening consciousness of being a subject. Teaching modesty to children and adolescents means awakening in them respect for the human person.
scborromeo.org/ccc/p3s2c2a9.htm#II