Not an elo booster, but I reached D5 before I retired from ranked. (got placed in Silver 1)
Here are some tips that personally helped me climb. They may not apply to you, as it's something I personally picked up on for myself during my climb. You might have already heard some of these tips somewhere else but I'll mention them anyway:
1. Avoid losing streaks - I had a rule where if I lost twice in a row, I would be done with ranked till the next day. Frustration is real with this game and it WILL negatively affect your gameplay. Wait till the next day to play with a clear/positive mind. I've seen people absolutely rageplay and lose over 5-6 games in a row knocking them down a division. Sure, you need to make some elo gains, but you also need to protect your rank from excessive losses.
2. Don't rely heavily on teammates - people will suck at this game. You need to give your 100% effort to make sure you're playing at the best of your ability. Be prepared to have junglers that won't gank, supports who don't put down wards, top laners who won't roam etc. Sounds cheesy but play smart.
3. Conquer objectives - I saw this problem at lower elo games especially. The issue with Bronze/Silver games is people are unfamiliar on how to close out a game. They don't push after they kill their opponents. They don't take any dragons till the 30 minute mark. They won't take Baron until the 40min+ mark. These games often drag on for long periods of time since people at these ranks don't commit on taking objectives. You need to ping/remind your team to focus on taking towers, pushing, setting up for dragon etc. If you kill your bot lane opponents 10min in, ping your jungler and take dragon! It'll take some work but some players need to be reminded of these things and trust me, it'll go a long way.
4. Avoid toxicity at all costs - if this means muting the dude who keeps making negative marks, then do it. If you're going to type, make sure it's something productive and is in line with winning the game. Avoid asking questions/making statements that invoke arguments among your team mates. Or playing the 'blame game'. Personally, I'm fairly silent in my games with the exception of making minor reminders like "drag in 1 min" or "mid mia" or "lets group up". I've been in games with a lot of trolls/toxic people who often rage/AFK if you argue too much with them. Yeah, they're scumbags at the end of the day, but they're on YOUR team and sometimes need to suck it up if they're being assholes and keep your mind on winning the game.
5. Play champs you are good at - don't focus on what the 'OP champs' are in the current meta. They won't be OP if you don't know how to play them at a ranked standard. I played champs which people would question why the heck I'm playing them but would often steamroll my opponents because I know the champion inside out. Have a small pool of champs you're REALLY good with and stick it out with them.
These are some tips that helped me out. Hopefully they can help you as well. At the end of the day, focus on having fun and enjoying yourself. Best of luck on the Rift
