Fabric
Pick a medium weight to heavy knit fabric with 30–50% stretch. For the collar choose a rigid but not too stiff rib knit that has a good recovery and 40–50% stretch. Make sure your main fabric and ribbing are approximately the same weight.You can use your dress fabric for the pocket bags or, if your fabric is heavy, pick a separate lighter but durable knit for the pockets.
Notions
35cm of ribbing fabric
30cm of pocket bag fabric for the dress