Here's a few suggestions.
1) Pathing markers - When you click to move and the four arrows animate, I suggest leaving a small circular marker (not necessarily a solid dot, but a detailed "designer" dot :P) on the ground to indicate where the destination is. This marker would change colors depending on forms of CC active on you.
Ex: Clicking for your life to escape a failing teamfight and you accidentally move your camera too far and lose sight of your champion. While spam clicking you see your destination marker on the ground change from green (normal) to blue (slowed) and realize "oh boy, looks like singed gooped me".
PS: This could also be used to tell whether or not your pathing destination is inside a bush or not. Because honestly, it sucks accidentally taking that 1 extra step and giving away your position. (Have it turn a lighter shade of the current color when on the ground in a bush)
- A secondary way of conveying CC information without actually needing to have your champion in view.
- Uses an area more commonly focused on during play. (It's safe to say you spend more time looking where you're going/clicking than you do looking at the buff bar below)
- There's probably an issue with the way players spam-click and how the marker would be constantly moved/replaced minor distances.
2) Pathing lines - This could be used with the destination markers, but a line on the ground to indicate where your destination is. Not necessarily following the exact path the game has decided on, but the direction the destination is in. This would extend from the feet of your champion and would pivot around the "pinned" destination marker, while changing it's colors depending on cc. The lines could also use arrows to display information, like this:
Ex: Once again you're running from a teamfight and your destination is a screen or two away from the champion. While spam clicking for your life, the line leading to your destination changes from green (normal) to red (stunned) and you realize ashe just arrow'd you.
- Another good way of conveying cc information using a more commonly focused on area of the HUD.
- Would also aid in keeping track of your champions position during fights.
- Might be difficult to see on certain terrain unless solid, non-textured and vibrant colors are used.
- Could be deceptive/confusing when auto-pathing takes you in a different direction than the line is leading (due to terrain and whatnot).
3) Gradient-stroke Champion Highlight - When you go behind friendly/non-friendly champions have a highlighting gradient-stroke that stays on-top of all other visuals to allow easier tracking of the players own champion. This can help minimize confusing from being CC'd.
Ex: You are playing rammus and initiate a 5v5 fight, you're winning but suddenly the enemy vayne breaks free and rolls out to begin dishing out the pain. You are unaware that you're cc'd however, and when you click to move out of the fight in her direction, you have lost track of yourself and don't immediately understand that the reason you haven't popped out of the fight is because you can't move.
- Easier to keep track of your champion during teamfights.
- More obvious when CC'd
- Visual hitbox issues (Is that going to hit my highlight or me?)
- Could clash with other spell effects flying around in a fight
I have more ideas, but I'm out of time for the moment. Will be back later :P