• A good way to develop your ear is to learn to hear how the modes can be arranged from brightest to darkest. I remember being surpised by one aspect of this when I first learned it many years ago.
• A useful way to think of "the modes" is how they compare to either the plain major scale or the plain minor scale.
• "Norwegian Wood" by the Beatles is in Mixolydian mode (though I doubt they were aware of the fact when they wrote it). Mixolydian is the same as the major scale, but with a b7.
• Dylan's "All Along The Watchtower" is in Aeolian mode (or, natural minor).
• I think the most useful modes are Ionian (major scale), Aeolian (minor scale), Mixolydian (major with a b7) and Dorian (minor with a major 6th).
• Phrygian, with its b2, sounds Spanish. Since Locrian has a diminished tonic chord, it would be very difficult to use.
• As always, trying to hum these scales is the best way to assimilate them.