Remember, you can add as many rounds as you like to your square.  Here is a pattern for up to 4 rounds.  You may want to make squares that are all one color, or a different color for each round.

FOUNDATION CHAIN: Chain 4; join into a ring with a slip stitch.

ROUND 1: Ch 4, (3 dc into center of ring, ch 1) 3 times; 2 dc into center of ring; join to third chain of beginning chain with a slip stitch. 

IF YOU WANT TO CONTINUE WITH THE SAME COLOR:
Slip stitch from the end of the round until you reach the ch1 stitch at a corner.  Continue with the next round. 

IF YOU WANT TO CHANGE COLORS:
Cut yarn, leaving a tail, and draw it all the way through the slip stitch to secure it.  Join the new color at a corner by drawing a stitch through a ch1 stitch. Continue with the next round.

ROUND 2: Ch 3, work corner (dc2, ch1, dc3) into the same stitch, work remaining corners: *ch1, skip over the 3 dc from the previous round, (dc3, ch1, dc3) into the same stitch; repeat from * two more times, ch1, join to third chain of beginning chain with a slip stitch.

ROUND 3: Ch 3,  work corner (dc2, ch1, dc3) into the same stitch, work remaining sides:* ch1, skip over the 3 dc from the previous round, dc3, ch1, work corner (dc3, ch1, dc3); repeat from * two more times, ch1, join to third chain of beginning chain with a slip stitch.

ROUND 4: Ch 3,  work corner (dc2, ch1, dc3) into the same stitch, work remaining sides: *ch1, skip over the 3 dc from the previous round, dc3, ch1, skip over the 3 dc from previous round, dc3, ch1, work corner (dc3, ch1, dc3); repeat from * two more times, ch1, join to third chain of beginning chain with a slip stitch.