How does upaya (skillful means) feature in Tibetan Buddhism? How does upaya (skillful means) feature in Tibetan Buddhism?

I'm just intrigued, because the texts I've spent longer trying to 'get' seem to be more inspired by the lotus sutra.
We say that contaminated virtue perpetuates samsara. The intention mental factor in the retinue of contaminated virtue is a contaminated mental karma that gives rise to suffering in the aspect of pleasant feelings (suffering of change). An example of contaminated virtue is the virtuous intention to give - generosity - in the continuum of an ordinary being. An example of uncontaminated virtue, however, is the mind of generosity conjoined with a wisdom of emptiness.

Here, when generosity is conjoined with both the wisdom of emptiness and bodhicitta, it is a skillful means because it is a uncontaminated virtue in the continuum of a being that never forsakes the welfare of others. So, every virtue in the continuum of an arya bodhisattva is a skillful means, since it is conjoined with both wisdom and bodhicitta.

In the Ornament of Clear Realization, Maitreya/Asanga say:


  The mind generation [i.e. bodhicitta] possessing skillful means, as
  the subject, is like a virtuous spiritual friend because by way of the
  four immeasurables, the method for not rejecting sentient beings, it
  never forsakes the welfare of sentient beings.


In his Commentary on Seventy Topics and Ornament for Clear Realizations by Geshe Jampa Gyatso:


  “Skillful means” refers to the fact that a bodhisattva with this mind
  generation is able to transform every single virtue into a cause for
  enlightenment. A virtuous spiritual friend is one who guides sentient
  beings on the spiritual path; in particular, one who is fully
  qualified is able to guide his disciples appropriately. “Not rejecting
  sentient beings” refers to not rejecting even one sentient being which
  if done would create negative karma and break both the bodhisattva and
  tantra vows.