The advice below applies to everything but snowy owls, which have very different behavior and can usually be seen from a large distance away. At least in the GTA where most snowies are at some distance on piers and breakwaters on the lake, I'm fully willing to post location. For other species, not so much.
In general it's hard to find any owl without disturbing it. I'd say about a third of the owls I've seen have been birds I flushed before noticing them. Many people will say that if an owl is looking at you with open eyes, you are disturbing it, but you will notice that this is the case for virtually every owl you see. Really, IMO, unless you're chasing an owl around and repeatedly flushing it, or baiting it towards roads where it can be hit by cars, one person's activities will not have a large impact.
The problem is that, in this internet age, any publicly posted owl seems to attract a crowd of paparazzi that follow it around every day from dawn to dusk, with a constant supply of pet store mice at the ready to get those ever-important flight shots. I'm exaggerating, but less so than you might think.
It's much more exciting to find owls yourself. Screech owls are omnipresent in the GTA, and Great Horned Owls are common enough as well. Going out after dark with tape recordings or just voice imitations may attract an owl in for flashlight views.
The best way to see owls in the day is to search dense conifer trees. Almost any owl will use them, and Long-eared and Saw-whets will rarely be seen anywhere else. Look for accumulations of poop and pellets on the ground and lower branches, as these signs are often easier to spot than the owls themselves.
The next best way to find an owl is by listening for angry birds. It takes some practice to tell when birds are actually mobbing something, but this is how I've found many owls, whether its crows harassing a Great Horned, Blue Jays a Long-eared or chickadees a Saw-whet or Screech.
If you spend enough time outside, you will see some owls, and it's much more satisfying when you're not standing in a crowd of people!
