QoL Mega-thread!
Work In Progress
This was inspired by Varus' Quality of Life change suggestion.
Please add your suggestions in the comments and I will add it to the main body of this thread if appropriate.
Remember quality of life changes are about updating old mechanics, ability indicators, and improve clarity for players.
###Varus 
- #####Ability Indicator
Current Q indicator is unclear for players for how it is to be used and it's range.
#####Solution
Make Varus' Q indicator similar to Xerath's Q indicator
Example
###Karma 
- #####Ability Indicator
Karma's Q and RQ ability have AoE that is not represented
####Solution
Make the indicator a line + an AoE shape to indicate it's size. Similar to Diana's Q or Frost Queen's Claim active ability.
###Zyra 
- #####Ability Visibility
Zyra's Plants can become lost in the fray!
#####Solution
Give Zyra's plants a thicker outline, possibly only when multiple enemies are nearby.
###Caitlyn 
- #####Ability Count Indicator
Caitlyn's traps have a limited number that can be on the field of justice but they are hard to keep track of.
#####Solution
Add an indicator 0/3, 1/3, 2/3, 3/3, and an "x" on the mini map to show which trap will be lost when adding a new one. Similar to the current warding mechanic system.
###Jarvan 
- #####Ability Range Indicator
J4's Flag gives no indication of the size of it's aura.
#####Solution
Add an aura AoE indicator around the flag in play when hovering over the ability icon. Or, when the flag is placed a faint AoE indicator persists. - #####On-hit Timer
J4's passive procs are limited to the same target every 6 seconds without a clear indication of when that time as elapsed.
####Solution
Add a countdown indicator similar to the one Yasuo has for E.
###Kog'Maw 
- #####Ability Range Indicator
Currently Kog'Maw can increase his range by activating an ability, no increased range is shown when hovering over the ability.
#####Solution
When player hovers over the ability icon, Kog's potential additional range is displayed.
###Lulu 
- #####Ability Range Indicator
There is no way to know when you are reaching the maximum range for Help, Pix!
#####Solution
When Pix! is in play add an indicator similar to Orianna's for her ball.
###Cass 
- #####Ability Visibility
Units that are poisoned become lost making it difficult to accurately follow up with Twin Fang.
#####Solution
When an enemy champion is poisoned they turn a shade green, similar to Rengar's ult.
###Diana 
- #####Ability Count Indicator
Diana's passive gives her an AoE attack every 3 attacks, if no attack is made the build up decays all without a timer.
#####Solution
Add a charge up count to the passive icon and add a countdown timer as well so players know when their next attack will be AoE and when it won't.
###Nautilus 
- #####On-hit Timer
Nautilus' passive procs are limited to the same target every 12 seconds without a clear indication of when that time as elapsed.
#####Solution
Add a countdown indicator similar to the one Yasuo has for E.
###Udyr 
- #####On-hit Timer
Udyr's bear stance stuns are limited to the same target every 6 seconds without a clear indication of when that time as elapsed.
#####Solution
Add a countdown indicator similar to the one Yasuo has for E.
###Lissandra 
- #####Ability Indicator
Lissandra's Q splits apart damaging a wider area of units than the indicator lets on and is unclear. This makes learning Lissandra a bit more difficult than it need be.
#####Solution
Modify Lissandra's Q indicator or add details to the tool tip to explain how this ability works.