One of the hardest groups of birds for birders to find sometimes are owls. It can be easy to hear them at certain times of the year and if you know where a breeding pair are you often get a good look. However if you know where to look and what to look for when you're out in the woods you can improve your chances of finding owls that might otherwise go undetected. Most often though seeing owls is a matter of being in the right place at the right time.
When I'm out in the winter time here in east central Minnesota, if I want to know if there are any owls lurking in the area I'm visiting, I'll look for telltale signs of an owl roost. For the elusive little Saw-whet Owl I'll check the Eastern Red Cedars along the trails I'm hiking. Every once in a while I'll find some "whitewash" on a tree trunk. This is a sign that someone is spending significant time in that spot.
A little patience and some careful skulking can reward a birder with a close up view of a bird that many people have never even heard of. If you do find a roosting owl, please keep a reasonable distance and try not to disturb the bird since any extra expenditure of energy can be a detriment to the wintering owl. But if you do get a look it will be well worth the effort!