I am a Leona main in silver that gets brain-dead monkey ADCs. Janna is good but with a bad team I get stomped on.
I want to find a good champion that can help brain-dead ADCs. But every time I pick an AP Champion I get flamed.
Karma and Bard need good teamwork and I don't have friends.
What should I do or play?
You pray!
Pick one of these and you can 1v2 the enemy botlane
what MLD said pick Naut and kill the adc with ignite and tld lvl 2 then get some hp and try to roam if your adc dies you shouldnt give a fk just get midlane ahead since most midlaners are braindead champions. Or if you are not mechanicly dead you can pick Brand and legit oneshot both of the enemy botlaners with one rotation or at least force em out of lane a couple of times and get the lvl advantage.
I pretty much only play vel'koz in ranked, as support too, but I got very little flame. There were a few "don't pick vel please" in champ select, but I managed to silence those protests in game.
Death is still the best cc and peel.
Edit: do buy the support gold item and sightstone though. A team really cannot do without.
It kind of comes down to your style and how well you understand a champion. I mained support earlier this season and only played 
& .
I been duoing with a buddy who recently just got back into the game. He just hit gold 2 last night and he mains 
& 
. I would generally stay away from blitz as although his hooks win games, missing hooks or hitting wrong target late game can really hurt the team. So you have to proceed with caution. I personally don't play blitz as I think he is a huge liability mid and late game unless a player is really good at hitting skill shots. But that is why my buddy really likes him since a late game pull on a carry can guarantee a win and he is honestly pretty consistent at landing pulls especially in lane so it has been working for him.
So really it comes down to your style and understanding your champion and its match ups.
Play safe, push through, and shine in team fights.
glhf
I used to play Leona, but I don't anymore in SoloQ. Usually, I think good Supports for SoloQ are Supports that either follow-up after someone else initiate (Braum) or react to the enemies and counter-engage (Morgana, Janna, Nami, ...), OR so called "carry Supports" that don't need follow-up damage from their team (Brand, Lux).
Pure Tank Initiators in Support position aren't tanky enough (due to low income) to survive long enough for a disorganized SoloQ team to follow them (whereas a Toplaner with a full lane income can, this one additional item is the difference between your mates following and acing them or you dying alone and being flamed). Moreover, they are especially hard to play from behind, since their main purpose is to create fights, and you don't want to fight when you are behind. But in SoloQ, you can't expect to be ahead more than half the time (unless you're under-Ranked/smurfing), and especially in a Duo lane where you don't know the other guy.
All that being said, my best winrate Support is still Sona, even after the nerfs following her OP mini-rework. Sometimes you just have to find THE champ that best fits your style and taste.
You need to play pro-actively as a support which is to mean that you have to essentially be a play maker. you should also play support as if you've got a big dingus and basically assert your dominance everywhere which a lot of supports in low ELO, don't do. If you already do this and your team still loses then they deserve to lose as there is no bigger letdown than a team that wants to sit back and bleed to death rather than make any semblance of an offensive context.
If you're really confident then you can just take one of the meta mages, rush sightstone into full dmg which happens quite often.
