When an issue is assigned to me, I figure out the next action and record it in the comments section right in the issue-tracking tool. The main downside to this is that I don't have a consolidated view of all my next actions for a given context: so, there are many conversations with myself like, "oh crap, why didn't I leave the query editor open so I could get info about these other 3 issues while I was in there?" Then again, I'm not that granular with my context lists.
In any event, I find it more palatable than copying much of this stuff into another set of lists.
When I assign issues to members of my team, I use the "follow issue" feature of the tracking tool instead of recording it in my @waiting list -- if I didn't do this, my @waiting list would contain a couple hundred items. This feature sends me an email any time someone updates or comments on the issue, and it is very easy for me to query the issues I am following. Maybe your tool allows for this too?