I've been trying to glue threads and thin cords and find it difficult. Using Yes works but it gets all over the page.

I have a few methods that work for me:

Glossy Accents (a very thin line)
Glue Lines
Glue Dots
Xyron
Staples

Sometimes I will just wrap the cord or ribbon around the back of my layout or card, and then adhere it with scotch tape!

I don't know if it is still available, but I have in the past used Wackytac which worked well. This is simply small sheets of adhesive. You press your string or ribbon down hard with a credit card to pick up the adhesive and then pull it up and stick it to your page. My packages are really old. One bears the K & Company label and the other shows a DCWV label. You might google it if you are interested.

I use Fabri-Tac (you can find it at Walmart) or strip of doubl side adhesives or glossy accents.

I use brads at each end.

I forgot about my xyron machine, that is a great idea, I use brads or glue stick, but I agree sometimes they have a will of their own

I use narrow double sided tape for small ribbon, and glossy accent for twine (when I glue it).

For a fun look I've started using color staples. It looks great with twine or ribbon.