Watch the Southern Rock online guitar lesson by Vicki Genfan from 30 Strumming Patterns You MUST Know
I'm using an Em-Em7-Am-Em7 progression here. This pattern is used in a lot of folk, rock and southern rock music. It's signature feel comes from the accent on the up beat of the 2nd beat. Make sure you're keeping your right hand and wrist relaxed as you keep the down-up movement flowing.
I've demonstrated it here with a minor chord progression. Try it with major chords or a combination of major and minor chords.