Misty I would use Royal icing and attach them directly to the edge of the bottom plate. I would use a #2 plain piping tip because it is more delicate, but if you find they break too easily for you, try a #3. Squeeze to attach to plate, as you move your hand from the starting place to the stopping place squeeze with just a bit more pressure, let the string begin to droop or drop down just to the level you want, as you bring your hand up to the stopping place and squeeze gently to attach. Make the upper string first, go all the way around the cake and watch carefully as yopu go to see they are all the same length and width, then do the bottom string the same way. If you try to do the double string one on top of the other it is too easy for gravity to take over and the top one can droop just enough that it touches the lower string, stick together and then you would have to remove both.
Practice on the edge of your turntable, or a bowl turn upside down and elevated off the table surface.
An alternate way of doing them is to pipe them singly onto waxed or parchment paper and let them dry, then attach with a little piped dot of royal on site. But I will warn you, you will probably break more getting them off the paper than you ever will piping directly onto the edge of the plate. And in piping by hand onto paper your lines will not be as smooth, especially is your hand starts to shake. Doing them freehand directly on the plate you will be surprised that each string almost makes itself, all you are doing is guiding it from one side to the other, gravity is forming the draped look.
Wow, Whirley! That's a gorgeous cake and GREAT stringwork!!
You did a most beautiful job!!! Gorgeous! Just had to pop in to say that and to say what a blessing it is to have Shirley around. Can you even imagine if the internet was not invented yet? Beautiful cake, just stunning and the stringwork is like the jewels on it. 
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