The bishops are urged to cultivate piety in devotional prayer and develop it:
185. Take care then, Venerable Brethren, that this true and solid piety increases daily and more under your guidance and bears more abundant fruit. Above all, do not cease to inculcate into the minds of all that progress in the Christian life does not consist in the multiplicity and variety of prayers and exercises of piety, but rather in their helpfulness towards spiritual progress of the faithful and constant growth of the Church universal. For the eternal Father “chose us in Him [Christ] before the foundation of the world that we should be holy and unspotted in His sight.”[Eph. 1:4] All our prayers, then, and all our religious practices should aim at directing our spiritual energies towards attaining this most noble and lofty end.
Bishops are also asked to provide formation for the laity in the liturgy:
186. We earnestly exhort you, Venerable Brethren, that after errors and falsehoods have been removed, and anything that is contrary to truth or moderation has been condemned, you promote a deeper knowledge among the people of the sacred liturgy so that they more readily and easily follow the sacred rites and take part in them with true Christian dispositions.
I understand there was an effort to develop missals in the vernacular after this. I have seen a few examples in libraries. Knowledge about liturgy is a good step. I think its placement here toward the end of the document, after participation and devotional life is an appropriate priority.
Bishops are urged to obedience:
187. First of all, you must strive that with due reverence and faith all obey the decrees of the Council of Trent, of the Roman Pontiffs, and the Sacred Congregation of Rites, and what the liturgical books ordain concerning external public worship.
188. Three characteristics of which Our predecessor Pius X spoke should adorn all liturgical services:
- sacredness, which abhors any profane influence;
- nobility, which true and genuine arts should serve and foster; and
- universality, which, while safeguarding local and legitimate custom, reveals the catholic unity of the Church.[Cf. Apostolic Letter (Motu Proprio) Tra le sollecitudini, November 22, 1903]