The trick to not becoming scum bait is to avoid doing the most obvious of scumtells: Passiveness, confusion, unsurity and defensiveness. While a townie should NOT be too concerned about the scumtells they throw, these four aspects are not helpful for any townie to have anyway.
Passiveness and defensiveness are signs that you are concerned more about yourself than catching scum. Since the goal for townies is to find scum while the goal of the scum is to simply keep alive, being too concerned about your actions means you aren't looking at others, including the scum...which is exactly what they want. Passiveness, meanwhile, is the same situation. In either aspect, you are spending less and less time finding scum and more time doing...something else. Every moment the town is doing ...something else...is a moment closer to a scum victory. To the town, there is the scumhunt or death.
lack of surity (the flip flopping you were accused of, for example) is trickier to pin down. Yes, it FEELS like the town should be less sure of themselves, since they don't know everything. However, I ask you this: how SURE can you be of declaring someone scum when you know, YOU KNOW, they are not? That's the mafia's dilemma. Townies, meanwhile, if they are doing their job, will always have someone they feel looks the worst. Even if they feel almost everyone is scummy, there's a "most scummy" among them. Even if they don't have a target, there's someone that catches your eye.. even for stupid reasons. Paranoia fuels a townie's power. Paranoia keeps them thinking "yes.. That person..they just might be scum!" and charging forward.
If you find yourself flipping from person to person early on..well that's scumhunting. If it's late into Day 1 and you're flipping around from action to action..you...or you.. or maybe you... end it..no don't end it.. then you need to pull back and reassess because something is off. Even if no one lynches you, the lack of focus means you aren't helping either.
Confusion, which the legendary WIFOM is based off of, is something that CANNOT be tolerated, even though townies can do it as easily as scum. The NK is NOT the mafia's most powerful weapon: Confusion is. Confusion defocuses the town. Confusion forces the town to second guess themselves. Confusion makes them stop being paranoid and makes them try to 'guess too hard' or think there's no real answer.
Confusion is poisoned wine, and it will kill a town FAST and HARD.
The other issues can be solved by just being more blunt, more aggressive... you don't need to screen your posts for it.. just play more like it and let things naturally fall in place. Confusion though.. avoid this at all costs. Don't force townies to 'guess your judgement' (why would I, as scum, do that?). Don't disrupt their scumhunting (disrupting bandwagons you think is on townies.. perhaps. Disrupting bad reasoning, ok.. but making them stop attacking or questioning people.. VERY risky). Be clear, open, and honest. Don't lie. Don't misdirect.
No.. I don't care if you are trying to 'confuse the mafia'. The entire town reads your posts. If you confuse them along with the mafia, I promise you, the mafia will recover faster and use your act against the town.
Note: townies can confuse people as easily as scum can-many times more often. But I promise this as well: if 3 townies are confusing the town then the town will lose.. simply put. Doesn't matter if the 3 are doing it on purpose or accident. Doesn't matter if the mafia helped it or just let it be. Doesn't matter WHY. I've seen the town have the entire mafia pack in their HANDS, and one line..one small line of confusion introduced by one townie resulted in a scum win. That's how destructive it is.
Avoid those four and...perhaps you may still get lynched..but you'll find you find scum much more often. Now if the town decides to lynch you anyway then that's on their heads, but at least you did what you needed to do.