It is a bit diffucult to give tips to different habitat
Long ago I written down advice on finding owls. I am citing it now. Enjoy it, but if anybody wants to re-print it, please cite me as an author.
"FINDING AND WATCHING OWLS
Most desired are daytime views, when owls roost, camouflaged, in tree hollow or rock crack, dense tree foliage, or pressed against tree trunk. One can narrow down a place where owls are heard at night. Old tree or patch of dense conifers are good candidates to scan patiently from distance to locate a camouflaged owl. Search for guano and pellets – balls of fur and bones spat out by owls (and many other birds). Roosts are also sometimes discovered by alarm calls and mobbing by songbirds or corvids – check such unexpected noise. Be very careful not to disturb a nest site, and remember that owls see well at daytime.
During casual observation at night, keep noise to minimum, esp. stay away from shuffling dry leaves or bushes. When using torch, shine to the side and bring it slowly to the owl. This makes it less likely to flush. Avoid shining at anything but an owl, especially your fingers or your colleagues. Note that an owl in bright light can look surprisingly pale with distorted contrasts.
Day birds flushed at night have slow, cautious flight and can be mistaken for an owl, eg. Red-tailed Hawk for a big species or a grackle for a small owl. Coots, rails, woodcock, many other waders, ducks, herons and nightjars are frequently active at night. They and their calls, as well as sounds of various mammals can be mistaken for an owl.
Owls are best located at sunset by calls. Be aware of variation of calls of each species. Remember also that owl at night is usually afraid of man.
Best observed are grown chicks after leaving the nest in late spring or summer. They are not shy and often call continuously. However, stay around only for a short time as parent owls are afraid and will stop feeding chicks in human presence."