This first example follows the E minor blues pentatonic box, and is a typical lick that you may hear Greg play. This is intended to have 'swing', but can be played with a 4's feel as well! There is a lot of room for variation, depending on the mood, situation, application, technical preference, etc.
Practice doing the slide vibrato with a 3-fret span, and also with a 5-fret span. Remember, the note marked with vibrato is where you are to do the slide, and you should be keeping the pitch as the 'center tone' of your vibrato!
Move on to the next example when you feel comfortable with this.