Hey, support main here. I know that sometimes it's tough in ranked since you're not exactly in a role that does flashy things like getting triples, smite stealing dragon, 1v3ing, etc, but it is possible to carry your team as a support (or at least aid your team in winning). I agree that getting ganked sucks especially with how the first blood turrets and dragons are right now, but it's simply something that's inevitably going to happen. However, there are some things that you/your team can do.
Judging from your profile, you play a lot of champions that do well in solo queue, so that's one step down! Your mastery pages seem fine, but there are some games where going Strength of the Ages is a good idea on Leona due to the extra HP it gives her (Legendary Guardian and Swiftness also aren't bad depending on what type of team you're against) or even Grasp since once she goes in, she's generally in combat long enough to heal. On Thresh, I would actually recommend going Thunderlords instead of Bond of Stone due to the nerfs that Bond of Stone has received. Thunderlords lets you poke in lane, and the extra arpen/mpen makes your E hurt a lot.
For runes, I suggest investing in scaling HP seals instead of the flat HP seals you have right now. The reason why most scaling things are unattractive are because you generally have to hit level 10 or so before they become better than the flat, however, the scaling HP evens out with the flat at level 6 and from there, it just gets better. In my opinion, you shouldn't need scaling CDR runes for Leona since caling Mr/Flat MR are a lot better for lane (if you're against something like Sona/Lulu) or if the enemy has an AP mid/top/jungle, which will likely happen. You usually cap CDR wise from your items. As for the movespeed quints, as Leona, you shouldn't be too worried about catching up to your enemy since you have both your E and R to set up combos. Most of the time, armor quints are a lot better so that you can go HP seals. If you'd like, you can invest in dual pen marks for supports like Leona/Sona/Thresh since their poke is improved a lot by it early on.
Your items seem fine, but there are some games where you should consider different boot choices. Mobility boots are amazing for initiating, but quickly lose their value as the game goes on and makes it harder for you to stick to people when you lose its passive. In solo queue, players might not follow up immediately on your ult as Leona and if you've lost your movement speed, you'll most likely struggle with connecting your E unless you flash/the person you ulted is nearby. Swiftness Boots usually guarantee that you'll catch up to your opponents as well AND you don't lose your movement speed when you're in combat. The slow reduction helps you stay on targets such as Ashe and Jhin as well. Merc Treads are good against AP focused teams or teams with a decent amount of CC in general. The less time you're stunned, the more time you have to peel for your adc. Ninja Tabi is amazing against full AD comps, or even 4 AD, 1 AP in some scenarios due to the armor. Keep in mind that a dead support =/= a good support. Building your GP10 item into a Face of the Mountain can be good as well because the naturally high HP on Leona means that you'll be able to shield for a good bit which can help your engages or even just to shield your ADC and Ruby Sighstone can be rushed due to its current cheap cost and the fact it gives semi-decent HP.
Gameplay wise, some ganks you can't really prevent, however, putting a pink ward in your tri bush (no matter what side you're on) is always a good start. That way, you can ward Dragon so that you have earlier vision for ganks if they're coming, but if they have someone who can go through walls (Gragas, Nidalee, etc), putting it in river bush is your safest bet. If you're on blue side and your lane is pushing up to the enemy turret, pop a ward inside of the tri bush beside their turret if you think it's safe for you to. Not only will you have vision of your enemy laner coming into lane, you'll also see if the jungler is taking Gromp/routing bot. You can also put it in the intersection at blue buff (red buff if you're on purple side), but only if your ADC is in a safe position and you know neither of you will get engaged on (best time is usually when the enemy bot lane has recalled). If you see the enemy jungler anywhere on the map, ping them so that you and your team know where he is (unless he's already killing someone, of course). It opens up the map for your mid and jungler to roam or play aggro. You can ping if the enemy mid/top laner are missing too. Just because you're bot lane doesn't mean that you can't ping that other lanes are missing. That way, if your solo laners don't ping, you and your adc can play safer knowing that there are people missing on the map. Take note of what summoners your opponent uses in lane and call it out in chat. You can tell from how they're playing if a gank is coming most of the time (if they're playing really far forward all of a sudden and you know they don't have heal and/or flash up, someone's probably coming). It helps your jungler too so that he knows what's down if he wants to head bot.
Anyways, sorry for the long post. I wish you luck on the rift and any future ranked games if you ever do get back into it!
) ... no matter how good I do, I can't carry a team. I can set up plays, make my ADC fed, and try my hardest to ward along with keeping enemies off my carries but ... alas, after dozens and dozens of ranked games, i'm starting to get utterly worn out by Dynamic Que. If the Jungler, Mid laner, and ADC / Support are friends, you freaken bet bot lane will be camped & ganked constantly, then i'm flamed for not saving my ADC.
