Like everyone else above has said,... glassing is key. When to glass isn't really a question... but where to glass is. On colder days youll find them out sunning, mid day or when its warm, they can tuck up under a tree.
I like to give my brother a hard time, on a family outing ... we came across some javelina. At first glance, they looked like rocks... but taking a moment, they moved a little... We took the kids to the wildlife world zoo when that happened. Out in the hill side a funny looking rock might be a sleeping pig, perfectly still.
that website someone mentioned above is awesome.
I know this is an older post (just got my leftover 37 a tag, so getting excited and thought id cruise this forum) ... theres a current thread in the campfire about tracking old sign.
Fresh poop, or old poop is hard to determine... or even worse fresh poop.... Ive hit the same spot two days in a row, only to have them poop in my boot tracks from the day before.