It is no secret that stitching abruptly curved fabric edges and seams can be quite challenging for sewing beginners or dressmakers that are not quite comfortable with their sewing machine or a difficult to control fabric. This is especially true when sewing on seam pocket applications which are often constructed using a circular curved bottom pocket bag.
Sewing tip: When stitching a curved pocket bag, use a temporary hand basting stitch to keep the curved pocket bag edges perfectly aligned during the stitching process. Even if you choose to only pin the top and bottom portions of the seam housing the pocket, hand basting just the pocket bag will provide an extra layer of the stability and accurate alignment along the entire seam.
Once hand basted, the curved pocket bag can be stitched more comfortably allowing you to focus on a smooth curved stitch application as opposed to worrying about the two pocket bag layers shifting out of place as they feed under the machine's presser foot. This is particularly helpful if working with light, flimsy fabrics that tend to be slippery during the alignment and stitching process. To ensure the hand basting is easy to remove when no longer needed, stitch right next to it and not directly on top of it.
When the pocket bag is complete, use a seam ripper (or a pair fo thin scissors) to pull the hand basting threads out as they are no longer needed.