The blind hem is gorgeous and a fast finish for most of your garments. I wanted to do a handpicked hem, which is traditionally done on lightweight fabrics. There aren't any raw edges to be seen; just a lovely finish.
Use your blind hem foot, which for the Bernina is foot no. 5. I used needle size 80/12 with 60 weight cotton thread. This matches the lightweight fabric of 100% cotton. Set your machine on the blind stitch. For my Bernina Aurora 450, this was stitch # 7, and needle in center position.
Set your stitch so the zigzag just catches both folds, with the straight stitch line falling off the edge (stitching in the air) to form a chain along the upper edge of your hem.
Turn your hem up 1 inch and press. Turn up again the depth of the hem. Press. The hem fold can be smaller, depending on your fabric and the amount of hem fold you wish.
Fold the hem towards the right side of your fabric. You only want about 1/8" to 1/16" of the hem edge visible.
Place the fabric under the hem foot, ensuring the fold is against the guide bar. The foot to the left is Bernina no 5, and to the right is a low shank blind stitch hem foot.
Sew along your hem. Remember, a stitch falls on each fold and the straight stitch sews "in the air", forming a chainstitch along the edge.
(left - chainstitch along fold, middle - front, and right - back)
Use matching thread and your hem will be near invisible! Quick and easy.