Comment below rating threshold, click here to show it.
Silver click around Kayle's feet. Play a practice game, click heal or the ultimate and move the curser around the feet, Kayle has a giant circular hit box it's just center at her feet 'cause she's floating in the air, once I figured out the hitbox is just slightly under the actually avatar I've never had anymore issues with casting things on myself.
Hope that helps.
And the Heal, when cast, puts a speed buff on you or that champion.. so if you've got the speed buff then it's pretty obvious you casted the spell. Hope that helps as well. There you go, both large issues simply solved ^_^