Ward. That's what diamond players do that you don't. As funny or as much of a joke as this may seem, it's true. Silver players are more likely not to ward then say a Gold 3 player. Vision wins games.
A few things just going off match History, is you like to change lanes often when you play. That's a mistake there. You should stick to the 2 main roles you have a high success rate in. If it's Jungle and Top then play those. If you Auto Fill, play someone safe and who can help the team. For example if you get ADC, don't be afraid to pick up someone like Sivir for the movement speed and utility for your team. It's about what you can do in those lanes/Jungle for your team if you don't get the role you want. (cause Auto fill in ranked is stupid anyway but that's another story)
Another is learning the champions. That's a major thing I see a lot of silvers Especially s5-2 doing. Is play FOTM champs instead of the ones they know. Yes FOTM might be strong, but it also puts you at a lower chance of winning because you aren't 100% familiar with them. You can play 20 norms and still not understand how the champ works fully. I'll take an example from myself. I play Anivia, FIddle, and Veigar mid. I am ok with the 2nd 2 and above average with the first. Reason being is I played a lot of Anivia when she was really popular. The other 2 were sort of picked up later last year and into this year after my break.
That leads me into my next point. Playing in moderation. The game is going to be there if you play or not. there isn't a need to play 12+ hours a day. You may not think it but it actually has negative effects then someone who would play maybe 2-3 hours a day. those people are generally calmer and more focused since they aren't playing that long compared to you who has. Pay attention to your games after the first one. You should see a better result within the first 3-4 games after then start to decline. In ranked do this. Play 3 games. if you win 3 play til you lose. If you lose the first 2 of those games tho, stop playing ranked for the time being for the day.
Last thing I would say is don't rely on videos on how to get better. They can only "help" you if you are willing to help yourself. Those players are Diamond for a reason and them giving tips and tricks to a silver doesn't always turn into the silver getting better overnight.If you want to get better directly ask people in game about things, or even here. A couple things you could utilize is Build pages like Champion.gg or Op.gg. Both are really helpful in that regard.
Hope this helps.
