2 toesHooved: deer, elk, moose, hogs. Shape and size take it from there - hearts point where the animal went.
4 toes, claws showDog family: coyote, foxes (and dogs). Wild canids walk tight, straight, businesslike lines; pets wander.
4 toes, no clawsCat family: bobcat, mountain lion. Round tracks, retracted claws, two-lobed leading edge on the pad.
5 toes front & hindBears, raccoons, opossums, skunks and the whole weasel clan - from mink to otter.
4 front / 5 hindRodents. Rabbits and hares cheat the system: watch for big hind feet landing ahead of the fronts in a Y.
3 toesBirds. Thick and huge = turkey; webbed = waterfowl; slender under cover = grouse and quail.
Carry a reference: a standard card is 3.37" long - lay it beside a print before you guess. And always read a trail, not a single track: gait pattern identifies more animals than any lone print.