gentle strumming is required, especially of the top(thin)3 strings, but listen to the song for accuracy.
intro- d g d a d
[ Tab from: http://www.guitaretab.com/s/stereophonics/49735.html ]
d a d a
The first time ever i saw your face
e g d
i thought the sun rose in your eyes
g d
and the moon and the stars, were the gifts you gave
c a
to the dawn and endless sky
and repeat for 3 verses until...
g a d
the first time ever i saw your face
and (g) till the end, and finish by picking thru (d) for a nice sound.