Watch the D Chord Pattern online guitar lesson by Stephen Mougin from Bluegrass Rhythm Evolution
In a D chord, the pattern is backwards. Pluck the D string, strum, pluck the A string, strum. Just like the G pattern, isolate the string plucks and practice with your metronome, adding the strums back in when you're comfortable.
Because this pattern is going down in pitch (rather than up like G and C), it'll take your pick a minute to get used to it!