The following examples show the five forms of C Mixolydian. As always, it is the positions of the root notes which determines the name of each form.
Open Position C Form

A Form

G Form

E Form

D Form

C Form

The mixolydian mode is favored by Blues based players like Robben Ford and John Scofield. Here is a line created from G Mixolydian.
When playing over a 1 minor to 4 dominant groove, it is common to alternate between the dorian and mixolydian as shown here.