In those cases where there is a community consensus that a user is a habitual troll, is there anything that we, as average Workplace users, can or should do to help identify the pattern of behavior?
As a community, we should be looking for problem posts, not problem users. If you see a question that you think is trolling, then follow the guidance in this answer from another Meta thread on trolling. If you see a problem answer or comment, then downvote and flag it for deletion or for a moderator. It is not our job to identify problem users, but by frequently (and appropriately) using flags, moderators should notice a pattern.
There is only once that I have specifically asked for a user to be suspended, and I do not think it should be done regularly. This is the wording I used when flagging one of their posts:
This user currently has three active answers (likely more that have been deleted), all with an extremely negative score. The answers I have seen all tend to offer very bad and damaging advice. I would ask that moderators consider whether a suspension is appropriate for this user.
In this instance I felt the user was offering possibly harmful advice, and that they had gone under the radar enough that they may not have been known to moderators. When it comes to suspensions and other actions to be taken against a user, that is the decision of the moderation team, not the community. If you notice a pattern from a particular user, then as I did, you are welcome to notify the moderators, but trust that they will take whatever action is appropriate for the situation.