Below is a nice video from YouTube demonstrating different strums. It's from ukulego.com
For "Don't Worry, Be Happy" and "Three Little Birds," use one of the reggae strums (#10 and 11) below (original images and even audio examples found at UkeHut):
For "Best Day of My Life," try one of the strums below for each chord picture.
For "Knocking on Heaven's Door," try the pattern below for each chord picture.
For "My Girl (the short version)," try the pattern below for each chord picture.
For "Count on Me," try the simple reggae strum for each chord picture.
For "I'm Yours," use one of the reggae strums (#10 and 11) below (original images and even audio examples found at UkeHut) or you can use the more challenging ghost pattern below those two.
For "I'm Yours," use one of the ghost strums (#8 and 10) below (original images and even audio examples found at Uke Tabs) or you can increase the challenge by creating an 8-beat pattern by putting the two together...8 and then 10.
The following songs have some really funky strums suggested within the videos. Not exactly simple strums or even ghost strums. Check them out!