Sometimes I've run out of thread in my machine or forgotten to stitch before I've taped down my panels. In these cases I just grab one of three things:
A Gelly Roll white gel pen
A paper piercer
A gel pen is self explanitory. I simply draw on my stitches. If you're worried about drawing in a straight line, don't panic, just grab a ruler! Personally, I'm not worried about a "handstitched" look with wonky stitches. In fact, maybe you want that effect sometimes,depending on the card and so a gel pen can be a better choice than a machine. Gel pens come in all kinds of colors and they even have puffy gel pens now so you can feel your "stitches". How great is that?
For those who haven't seen a Scorbug before, it is a cool little tool with a retractable wheel with spokes that pierce the paper as you roll it down a groove. I use my scorpal board so that I can line up where I want my "stitches" but if you don't have a scoring board you can also use the groove of a kitchen table or something similar.
The Scorbug doesn't pierce all the way through the paper. It simply makes dents, see?
And when you flip the paper over, you have an embossed stitch line like so... this is the side that I would want showing on my card.
There's also the handy little paper piercer/embosser. See below. Using the sharp end, simply poke holes in your paper (with a strip of carpet or foam underneath to protect your surface) to make a "stitched" border . You could also then hand stitch through the holes but I'm not that ambitious. I would leave as is (as it looks quite nice), or, every third hole I will poke the needle all the way through . See how the piercer has a sharp tip but goes thicker as you go up the shaft? If you pull all the way up the shaft you'll have a bigger hole and can achieve a nice "eyelet" effect with patterns. You can see what this looks like back at the first picture, top line.
(I'm sorry if its not very clear.)