I tend to have two distinct approaches to those kind of games. If I go heavy on the roleplay then I can build my character on the fly without giving it a second thought - in that case the thematic of the build matters more than power and I try to explore some unorthodox strategies or go heavy on consumables or try to play a pacifist card (if it suits the character). I tend to separate each character from my real self and write them like a book with a strong emphasis on appearance - it should be unique and carry the vibe I am aiming for through the whole story. This approach I usually go for on my first run.
Powergaming and theorycrafting kicks in later, on a second and consecutive playthroughs, where I try to push the boundaries of gameplay or create unique builds that can refresh the experience.
