In this post I do not want to describe the characteristics of this public cult in the past (at present very difficult to perform in its original expression): I'd rather prefer to provide some brief consideration useful (I hope) both for an eventual private cult and for the understanding of some related implications and meanings which can help us to maintain our personal status of "awakening" and "awareness".
Liber and Libera are fecundity natural forces (not accidentally cited during this month dedicated to fecundanting Mars), above all a fecundity linked to wild Nature particularly active in the forests; they are mainly active during the transition or passage periods such as Spring and Autumn.
Liber in
particular is the trees' cortex, above all the cortex richer of life and sap connecting the leaves to the roots. Liber/Libera are "Deities of the Sap", "The plants' blood". They are underground forces (included in the triad Ceres-Liber-Libera) which every spring emerge from the ground to resuscitate plants and trees.

Thanks ot these forces, trees can be covered by leaves and then by flowers. Liber/Libera are forces of the Sap, pollen and nectar as well as any kind of lymph: for men and women, Liber/Libera are linked to the maturity of sex organs and the related fluids as tools to animate Nature
We can use this Ode by Horace as invocation to Liber/Libera
Bacchus on the far-off rocky hills, teaching
his chants -- you who are still to come, believe me --
I saw him and his student Nymphs and
goat-footed Satyrs and their pointed ears.
Euhoë! -- my soul trembles with that moment's fear,
Bacchus possesses my breast and I madly
rejoice. Euhoë!, spare me, Liber,
spare me, god of the fearful rod of power.
I must celebrate your inexhaustible
revelers, and the fountains of wine and full
rivers of milk, and mirror in song
honey dripping from the hollows of trees...
Horace, Ode 2.19