I'm not really an accessory person, in any part of my life, whether it be sewing, decorating, or just dressing myself. But I can say that your choice of thread on any project can make all the difference. I use a khaki thread on a lot of my projects, partly because it matches nearly everything and also because it adds just a delicate border. Most people won't really notice it's there, but without it a project can seem so boring.
So my advice, always choose your thread carefully.