Hi there! I am currently a Silver I support main and I can tell you that I feel your pain. One of the bigger "jumps" in ranked is where you are (Bronze I-->SilverV) right now. This ranked area is difficult to go through usually because the skill levels can vary quite a bit. You can get players that know what they're doing (kinda) and just climbing--and people that just became level 30's the night before....the skill discrepancy is alarming. The best advice that I can giveI you is really to work as a team, use common sense, and keep a good attitude. Anyway, here are some tips that I have found useful.
~~In the champ select, always try and get what you are best at, yet be flexible. Basically, instead of saying "mid," try and say something like "mid is my best but I can support or top if needed". By saying this, you are telling your team what you are strongest in, yet at the same time are also telling them not to put you as adc or jungler. There's nothing worse than being forced on your worst role because that is all that is left no one knew otherwise.
~~Be strategic when you ban. Just because everybody bans tristana and lee sin doesn't mean you have to. I struggle vs Morgana and Yasuo (so do most people as well) and I ban them because of it. My last ban is usually teammate-requested. I might say something like "is there any champion that someone truly struggles against?" Just the other day a Vayne told me that she really struggles at dodging blitz hooks. So I banned him and we won the lane (maybe because of it maybe not). It gives people some relief and gives you a greater sense of teamwork.
~~DO NOT RAGE. Easier said than done, but never rage at your team no matter what they did. I almost always lose when my team is having a riot (pun intended), If your team is losing because the top laner is struggling, tell him to play it safe and not overextend and ward (in a nice manner). If you are the jungler, or mid, gank as needed.
~~WARD. These cheap things can save lives and games. Warding can ofc vary based on your position, but do not neglect it. If you have 100 gold, that gold may be better spent on a ward than 3 pots. At the very least have a pink ward SOMEWHERE. The river bushes, your own red buff, anywhere helps. I personally like having a pink in the bush besides your own turret if I am top or bot purple side since it can spot towerdives. Don't forget the trinket as well. As a support, I like to have 2 pinks on me at all times. One placed on the map with another in my inventory. That way, I can use the pink if we are doing dragon.
~~Be able to read a gank. There are a lot of tell-tale signs to identify an incoming gank. Here are some examples:
@The enemy champion places a pink in a bush that is in the lane (especially if you've been zoning them previously)
@The enemy champion(s) are letting you push the lane abruptly.
@The enemy champion(s) starts 1v1ing you out of nowhere (especially if you are ahead of them)
@Summoner spells are used in conjuction with a skillshot. That flash was used since it was imperative that you were cc'd
~~If you spot the jungler or mid laner in a bush because of a ward (like you should be doing), you want to play it safe but you dont want to completely flee the scene. You WANT them to stay waiting for you to go-in because it wastes their time or gives you some extra. A jungler wasting a whole minute in the bush could be using it to farm or gank elsewhere. Your jungler could also use the oppurtunity to gank another lane "counter-gank" free. Alternatviely you could buy your side some time to get over there and ttack the fool siting in the bush.
~~In a teamfight, try and gauge what is best for the team. Sometimes, your team is miles ahead and you want to go ham on the adc. Other times, their team is ahead but your koggles is well-farmed..protect the thing at ALL COSTS. Most games however you want a combination of the two. A dead adc usually spells death of your team unless someone on your team is immensley ahead (yi).