Since Niantic didn’t feel like creating a support website or any instructions for Pokemon GO we will try and help with some tips and tricks as much as we can!
How to Track Pokemon
Since people act real surprised when I tell them this in the comments, I suppose this isn’t something that is widely known.
Whenever you tap the nearby bar and tap on a pokemon you want to find, he/she/it will occupy the lower right ‘nearby bar’.
Then whenever you walk into the direction of that pokemon, the bar will blink.
Keep doing this until there are no more footsteps and the pokemon should spawn.
Edit: And for the love of God, do look up from your phone sometimes. You don’t want to end up under a car or in a river while chasing that Rattata.
Also, a couple of people seem to have trouble with this tracking method. Here are some additional tips.
Be sure to select 1 specific pokemon and make sure it isn’t already visible on your screen (every pokemon you see, be it in or out of your circle can be caught and thus the game considers you ‘on top of the pokemon’ and will blink in every direction).
Also be sure you didn’t select a pokemon with a duplicate nearby (I’m not sure about this, but it could be that it will blink for both).
But if you’ve selected 1 pokemon, not visible on your screen at this moment (and with no duplicates nearby to be sure) it won’t blink in every direction you walk to. Also make sure your avatar faces the direction you’re walking.
By the way you don’t have to select one specific pokemon. If you won’t it will blink when you move in the direction of one of the pokemon shown.