Ribbon stitch is easily the most important stitch in silk ribbon embroidery. If you learn how to do it, it means you know almost everything there is to know about stitching with ribbon. The stitch is used in great many silk ribbon designs and patterns, mainly for stitching petals and leaves. It is very hard to create a pattern without this stitch, so you can hardly find one. There are are slight variations of the technique if you need a pointed petal or a slanted leaf, but all of them use the same steps as for a regular ribbon stitch. Here is a small tutorial on how to make a regular ribbon stitch with silk ribbon (click on the images to enlarge):
1. Bring the ribbon through to the front, flatten it with your fingers and lay it in onto the fabric. Insert the needle where you want the stitch to end, piercing both the ribbon and the fabric beneath it. The needle should be inserted precisely through the centre of the ribbon, i.e. having same distance from either edge. Make sure that the ribbon has not twisted, and that you have flatten the ribbon before you make the stitch.
You can make the stitch with 2mm, 4mm, 7mm, and even 13mm wide silk ribbon. The wider is the ribbon you pick out, the larger flower you can stitch. Bear in mind, that you need to use right needle when working with wide silk ribbon.
Daisies in the photo are stitched using 4mm wide white silk ribbon. You can make such flowers easily if you work five petals with the ribbon stitch.