Aren't you feeling like there's some features that should've been an obvious implementation? Compared to other games, League of Legends feels very unpolished when it comes to convenience.
I'd really like to see the default mastery and rune pages as well as summoner spells in champion select change to the same as you had last game you played the champion. Quickcast options should also be bound the to champion, not in general. This is always annoying when you have a mix of normal cast and quickcast, champions have different kinds of abilities on the same hotkeys, it makes no sense that it's not champion specific.
Being able to set your account to "offline" would also be nice, sometimes you don't want to be bothered by your friends and just have some silent solo Q matches.
It's so obvious and convenient, why do Riot insist on keeping their client in such a sub-par state?