You have likely already made an infusion:  maybe you've added water to rehydrate chia seeds or made sun tea. Chia seed rehydration is a cold infusion, while sun tea would be a hot infusion. Basically an infusion is tea over time.  

To make an infusion, in this case an infusion of pine needles, you boil 16 oz of water, pour it over a handful of pine needles & let steep for as a little as 15 minutes up to 12 hours.  Yes, the prime time to harvest pine is in the summer when the needles are new & liveliest, but during wintertime pine is one of the few viable seasonal foods that is not a root. 

It's getting toward the end of winter,  but it's still holding on. I like pine infusion this time of year because it's gently stimulating & I'm feeling like I need a shove of motivation. Winter time affords a lot of sitting around. I lounge for hours in my sleepwear (old sweats & hole-y socks), I move slowly when I move at all, I eat foods that are thick & warm & stick to my ribs. Pine helps me move through & out of stagnation. It's also especially high in Vitamin C, which is convenient considering I live in a city where I eat delicious fresh citrus so long as someone's grandparents mail it from Florida.  Fun fact:  had Native Americans not been so generous with their pine needle infusion all the Colonists might have died of scurvy...marinate on that, INFUSE on that. 

If you find yourself near some woods or in McCaren Park help yourself to needles that have fallen from the tree, take them home, give them a warm bath, & season with honey.  Sit quietly & comfortably as you are relieved of stagnant digestion or a cough that won't move.  At the very least you'll feel at peace.