You don't have to win lane every game to climb. Quite frankly, a lot of people underestimate the important of not losing lane.
While winning your lane and snowballing can be quite useful for deciding games (especially in lower ELOs where people make mistakes aplenty), all the really matters is that you become as strong as you can. Farming well and (most importantly) not dying to your opponents will bring you much further than playing aggressively to crush your opponents since it is far safer and more reliable.
For a lot of champions, "winning" lane can be defined as reaching your core items at a reasonable time or going even in lane (i.e. late-game champion against a lane bully).
I'd say that there are three very important abilities which will easily carry a play to Gold (at minimum) with little effort.
- Farming (to reach your champion's power spike and to have a reliable source of gold).
- Rotations (knowing where you have to be and when, shot-calling for your team, predict what the enemy team is doing or wants to do)
- Maintaining a positive attitude (stay positive, maintain team morale, try to prevent or end fights)
After a certain point, all of these become instinctual.
Another tip is to play to the ELO you are in. For example, I found that Silver players would often:
- Pick damage-heavy and squishy champions
- Had horrible laning mechanics
- Would constantly group around objectives at poor times
- Didn't know how to close out games.
To take advantage of these weaknesses, I played a significant amount of Gragas, Varus, Ziggs and Nasus. When we grouped around objectives, I would poke them down. When someone mis-positioned, I would catch them out. My lane opponents wouldn't know how to play against me and shut me down, so I would scale. And when teamfights began, I could lock them down and split them up.