I'm a casual guitar player, I don't have any aspirations to be a lead guitarist or anything like that, but I'm good enough that I can hear notes tell what they are, play the chord etc., the way I practiced was I would look up songs that interested me, but were'nt overtly complex, then I would find out what chords were in that song, then throw away the song, forget about it completely and just look at those chords, memorise the positions, and practice playing them in random orders until I was able to play it (relatively) flawlessly, then afterwards I would go back to the song and it would be really easy to play, and not only that but I also knew those chords, then I would pick another song, and repeat. That's how I started at least =p