Watch the Brush Stroke online guitar lesson by Chris Buono from 60 Electric Guitar Techniques You MUST Know
An alternative to strumming with a pick is using your pick hand for a technique called brush strokes. The combination of a lighter touch and a less harsh material making contact with the strings equals a softer, more subdued effect when strumming chords with brush strokes.
Another, more advanced approach with brush strokes is playing octaves with your thumb. Look no further than the great Wes Montgomery or his predecessor George Benson for what is widely considered the ultimate approach to playing octaves this way. The resulting tone and phrasing potential is incredible when mastered.