Be selfish. I carried myself (for the most part) out of bronze this past week after I started playing my main in a carry role. At first I was not confidence with my skill level with my main, but as I kept succeeding my confidence and elo grew. Before I would play jungler picking a meta pick rather than focusing on a favorite pick in a mostly carry role. I would constantly be whatever for my team playing meta picks rather than being selfish and play my favorites in the chaos of partially solo queue. It's working so far, and it continues to work for me.
TL; DR: Play a role you and play whatever you want
gl hf