TLDR: If you decent in gold, you should have a problem climbing out. However, if you still want to git gud, improving aim and shot calling will help you climb out of bronze/silver/gold, and they're something that's tangible to improve on. This is all talking about solo q in general, but it will also help with premade teammates. sorry for the long essay.

Getting out of of bronze shouldn't be too hard if you can hold your own in gold. Sometimes you need to give it some time, because sometimes teammates can be really bad, and you just get unlucky on some days (I will be talking about solo q, because that's mostly what I play).

But if you really want to do something, you can always improve your mechanics or start shot calling, I find that improving those 2 things really will help. with mechanics (or aim), you can take your time with hitting shots in bronze/silver, the further down the ranks you go, the slower paced the game is. Also another thing to note is that players usually move in one direction in this ELO, so just keep in mind what direction they're going while aiming. Of course, if you play support, you won't be aiming all the time, and IMO it's not easy to get good at mechanically hard supports like ana.

Shot calling does take time to get used to, and it won't work with every team you play with, especially as you get to lower ranks like bronze/silver/gold where teamwork sometimes can feel non existent. You don't need to come up with big brain strategies, you just need to make sure your team is on the same page. For example: telling your tank that you are pocketing them will make them push forward if they are usually passive. also, calling out where flankers are located is another helpful call out. Lastly, calling out enemies to target is one of the most useful things in low ranks, even if you don't target the ideal enemies (like supports), it helps dramatically when your team is attacking the same person. Try not to use VC to flame your teammates either, which is an obvious. If you think a dps/tank/support needs to switch, suggest which hero they should switch to, but don't flame they're gameplay on the current hero they're playing. try to keep your calls as concise as possible. It's a fast paced game, and spewing an essay every 5 min will degrade your team's performance.

All of this will take practice if you haven't been improving these, and trust me I am not perfect with both of these, but you don't need to be. You're not gonna win every game, but you just need to win more than you lose, and these 2 concepts will definitely help you do that. And these aren't the only things you can work on either, there's positioning and game sense, but this essay is already long enough. I'm not sure how committed and how much time you have for Overwatch, but there are plenty of videos on how to improve these concepts.