Spline mode has the ability to insert and remove nodes to adjust the shape. If the curve is too far away from the outline you want, simply add more points on the outline where the shape you have is ‘most different’ or furthest away from the artwork.
It is often best to begin with minimal nodes in the outline, only basically representing the shape you are drawing. Then, go back and insert only the nodes that are needed to pull the outline into shape. Doing it this way, you will use a minimum of nodes.
Why use a minimum of nodes? The stitches being generated have to look at all the nodes on your shape. If you insert hard nodes or cusps, the needle will penetrate at those nodes, so you get less desirable embroidery and an increased stitch count. Another reason to use minimal nodes is for editing purposes. Suppose you test sew your design and realize you need move overlap for registration issues – the fewer nodes, the easier and faster the edits can be accomplished.