Know your enemies, and know your supports. It's not easy with so many members out there, but the more you know what your enemy kit has the better you know how to adjust to them.
I stress know your support as well. Be aware of their skill and play-style, at least in general to adjust to them. For instance a poke focused support may not be as good at doing an all in attack. You may need to wait a little, for the support to poke the carry down further, before going all in since your support won't be able to burn them down.
awareness of heal potential is a big one too from a healer point of view. If you have a healer with strong heals, like soraka, their eager to heal you. You may wish to play a little dangerously, make trades, even some were your take a little more damage then the enemy carry, if you have a better healer then them. A healer with full mana is not doing anyone any good.
On the other hand though just because a support has heals doesn't mean they want to use them. Taric's heals are weaker and best used when both he and your taking damage, sona heals are only efficient in team fights and so she builds her poke early on. Only take extra damage if you have a healer who is full mana or clearly has good early sustain.
The point being remember you have a teammate, and adjust to a style that works with both of you. Your not alone.