Rikaisama's definition of 先 includes meanings like previous; prior; former; some time ago. However it also includes meanings such as front; ahead; the future; destination. I am struggling to make sense of when to apply each meaning since it seems to me that they are pretty much the two sides of the same coin in one word. There's also 先に which can mean before; earlier than / ahead; beyond, among others.
I've noticed that if the meaning has to do with the past, the subsequent verb is in the past tense. This is a good starting point, but it doesn't always help me. Am I forced to learn each usage of 先 individually or is there some "rule" to the word that would help me identify it's meanings in different contexts?
Thank you in advance.