Whenever I start counting the CF Tags I know one by one, Geometry Always comes almost the last, I think it is very unpopular on CF aswell.

Geometry problems, add more geometry problems
I have seen a lot of great adhoc ideas be used in several topics and tags, but geometry and some others occurred very rare, I think trying to take advantage of such uncommon ideas may help in getting ideas for problems.

I have noticed though that in the early years of codeforces some really good geometry problems were proposed, I think it will be cool to revive this era.