This is a very general question. Do not "chose" an approach. Evidence Based Practice for Physiotherapy in reducing spasticity does not reflect the extremely effective treatments that we can provide. Review the new definitions of the term "spasticity", and recognise the many components that may lead to spasticity- Hypertonus, hyperreflexia, biomechanical shortening, adaptive postural responses(associated reactions), etc.. Decide on what and where the underlying lesion may be, and what plastic adaptions since has taken place since the insult. Many facilitatory techniques can reduce the unwanted "noise" of spasticity, but don't forget to turn the facilitatation toward functional activities based on the patients goals.
Such an interesting topic! Goodluck.