A 'traditional' approach to the post-conciliar Divine Office would start, I suppose, with the proper implementation of the rubrics that are in the Liturgy of the Hours. Thus incense should, when the office is in common, always be used at the Gospel Canticles at Morning and Evening Prayer. This reproduces the Sacrifice of Incense in the worship of the Temple in Jerusalem, and, quite apart from reminding us of the proper dignity of those canticles and of those who uttered them (our Blessed Lady and S John Baptist), recalls the Temple basis of our worship and the Hebrew basis of our whole Faith.
And real doctrinaire enthusiasts for Vatican II could recall the assumption made there and expressed in the decree Sacrosanctum Concilium that the overwhelming majority of clergy apart from a few duffers would continue to say the Office in Latin.
Then there are things unmentioned in the new Office but arguably assumed, such as the old custom of Deo gratias at the end of Brief Readings and Tu autem Domine miserere nobis - Deo gatias at the conclusion of longer ones. [Thanks be to God; But do thou O Lord have mercy upon us: thanks be to God]
And next, things deliberately omitted but easily restored, such as the full dialogue (as in the Prayer Book) before the first office of the day; and the use of the versicle, response, and collect after the Marian anthem.
But these are slight details compared with my next suggestion. A big loss in the liturgical reforms was the concept of 'commemorations'; the idea that, as well as observing the Saint of the Day, just one observance on one day, the person praying the Office 'commemorates' some other saint. In the old rite, this meant that one remembered a saint who in a previous age of the Church had had a considerable cult, which had now faded and been overlaid by a more recent observance. 'Commemorating' created a diachronic unity with our fellow-believers of earlier centuries. And if one 'commemorates' a saint who is important today in some other part of the world, there is a synchronic unity with fellow Christians in another place now. As an ORDO compiler, it always irritates me that when one comes to November 17, one has to choose between S Hugh and S Hilda and S Elizabeth, or else subject one or more of of them to the indignity of being shifted off their 'proper' day.
'Commemorating' involved saying, after the collect of Lauds and Vespers, the following elements from the Office of the saint you are not treating as the main saint of the day but wish also to remember: the Antiphon which accompanied the Gospel Canticle, plus the Versicle and Response that followed the hymn (one could in the new Office use the Responsory or part of it) plus the Collect.
I remind readers that it is perfectly lawful to use parts of the old Office- Dominical and Festal Lauds and Vespers spring to mind - in place of the forms in the Liturgy of the Hours. One could for example use the ancient text of the Venite and the old usage of invitatories.