Stop with the auto-pilot and handicaps on champions
Can we please get more champions designs with less mechanics shoved into the natural flow of the champion's kit just to add power into their design, with no real additional effort on the player's part.
All of the champions who actually require any degree of continuous effort to play effectively (beyond muscle memory after the first 5-10 games) are often given such massive power budgets that it compensates for actually needing to put that continuous effort into the champion.
Basically, lower the impact of the difficult champions and/or cut down on the kit management handicaps. If a champion is going to be 3 times more complex than
then they should be consistently 3 times harder to play.
This means, stop with the extra passives attached to active abilities, stop with the multi-stage abilities, stop with all of the fluff in a kit which requires zero, or less than previous, management of information for benefits. I'm looking at you 
The most mechanically complex champions, should naturally have the lowest win rates. Yet they constantly don't, they're given handicaps with their numbers and mechanics based on the results. I'm not talking wall of text abilities for "complexity" i mean things like, timer/stack tracking, actual skill shots (not impossible to miss combo pieces), and skills that can backfire for fizzle based on usage criteria.