Currently, when you are looking at any discussion or idea board from the list view (aggregated), you can't tell whether you've already upvoted for something unless you hover over the upvote icon to see the message on hover that says 'click to remove upvote'
All ideas look the same, which can make it difficult to keep up with the latest ideas and know whether you've already reviewed the idea.
For example, in this view, I have added an upvote to the middle idea, not the one on top or bottom, but all 3 look the same afterwards:
Once you click on an idea, you can then see an indicator that you've already upvoted, but would be nice to know before clicking through (or hovering):
maybe it's just me who can't remember every idea I've reviewed, but I think this would go a long way in helping more people stay involved and being proactive with new ideas, not just their own.