Make new friends,
But keep the old.
One is silver
and the other's gold.
The song is about new friends vs. old friends, but really it's not new or old, it's how deep the friendship is, especially with our digital age. Old friends tend to be deeper because we have had longer to share more of our lives with them, but older doesn't mean deeper.
Deep friends are friends with whom you can comfortably share anything in life: your most private challenges to your most petty triumphs. The more of these sorts of things you're comfortable discussing with a friend, the more intimate the friendship.
Technology can be a big barrier to intimate conversations, so plan activities with friends that encourage deep conversations (something beyond the weather, movies, politics, like the meaning of life, hopes and fears, and even your crushes). Camping works well for this, even with a larger group.
When building your social circle, don't go for quantity. Go for depth and deeper sharing. Go for intimate friendships. Deepen those friendships now.