Slagg, a distinguished alumnus of the renowned Vancouver Playhouse Acting School, began his professional journey primarily in the realm of theatre, before transitioning to film and television. His artistic approach is deeply rooted in the principles outlined in Harold Guskin's influential work, "How to Stop Acting", which serves as a foundation not only for his acting technique, but also for his coaching and theatre directing endeavors.
Slagg emphasizes the importance of going beyond mere technical proficiency, stating that "actors know how to walk about and say lines to each other, that is trivial; the work is to discover the essence in the action, the heart in the words". He recognizes that the true challenge lies in uncovering the underlying essence of the action and the emotional depth of the words.
However, Slagg diverges from Guskin's perspective by believing that intuition, a crucial component of a genuine performance, can be cultivated through education. He advocates for a comprehensive study of the script, including intentions, beats, physicality, and other aspects, with the understanding that when the actor has fully absorbed this knowledge, they can confidently surrender to their intuition, knowing that it will access all that has been learned.