I've only played one scum game, in a relatively "easy" setup, but I didn't find that I needed to motivate myself to perform, nor did I have to really do anything different than what I would do as a townie (other than knowing what alignment that person was going to flip, ofc) :o

I'm sure it would get boring eventually, but my mindset during that entire game was that I WAS a townie.

I think a key thing, though, is that I naturally filter all of my thoughts so that they intentionally (at least attempt to) sound like I'm town. Even as town, I try my damnedest not to say dumb things. So, when I rolled scum, I just kept playing like that.

Sure, small sample size, but it worked well for me :o

E: Basically what I'm saying is that if you have to differentiate your mindset, you're already doing it wrong, IMO.