Each patch will begin the stitching at one of the nodes of the drawing. If you want change the starting point of the stitching you can.
This heart begins stitching at the bottom of the heart.
Stitching can begin any place on the patch. If there is no node where you want it to begin stitching, simply use the Shape tool to add a node. Then use the Set Start Stitch command to assign the stitching to start with the new node.