I actually just came here to make a post about this. My idea is for a target ring around your champion. I played a game last night as Talon, I had a Cho and and a Naut on my team, when I would dive into a team fight I completely lost sight of my Champion.
I think a UI option to add a target ring around your Champions's feet would really help new/less skilled players in improving their gameplay.
Now, I can already see the argument against this, especially when it comes to ranked play and the pro-circuit. There are some very easy ways to deal with this:
* Disable the target ring in all ranked queues.
* Disable the target ring at level 30.
Now, the issue arises with players who have heavily relied on the target ring and now want to play ranked (or hit level 30) and its gone. To fix this I'd love to see something where the opacity on the target ring gets lower and lower from levels 20 to 30. So levels 1-19 you have a full vibrant ring. Then each level from 20 on the ring fades a little until it is completely gone at level 30. This will basically allow players to phase out the use of the target ring.
In all honesty I don't see a need to disable the ring at level 30 or in ranked. But if it was deemed an issue the above suggestions would take care of it.