When suggesting nerfs avoid these words...
"Gut", "Remove", "Delete" in reference to a kit or any part of a kit is generally going to garner only negative responses. Nobody wants to hear how "Ashe's slow is annoying gut it now!" Oh yes... let's... gut what makes Ashe, Ashe. Totally reasonable fellow here.
Mechanics can be tuned, numbers can be trimmed and pointless stat boosts can be reworked/reconsidered. But the moment your post consists of "Lucian's passive is broken please delete it and give him something else!" Most people won't take you seriously. There are 134 champions and millions of players. Somebody enjoys that champion, the entire community isn't nodding along like "yeh you right bro. Fuck lucian"
Conversely, when suggesting buffs to a champion avoid adding new large features or massive overtuning of multiple abilities at once. Buffs and nerfs should be incremental adjustments to the kit and numbers. To bring champions in line in a healthy manner.
If a design baseline cannot be balanced with small, incremental changes
Riot reworks them. So if you absolutely think a champion cannot be balanced, which is very rare, suggest a rework.
Don't come on the boards going "omgwtf Xerath can never be balanced remove his mana return passive and gut his ult damage!" Nobody but 1 or 2 other haters of that champion are going to take your post seriously.
infinite kiting
going everywhere
utility assassin