While sitting here at work working on sling patterns and dieing of boredom poisoning, I brought up a video I posted earlier (http://www.youtube.com/watch?v=DNimz7JCTiI&feature=youtu.be ) and took notice that some had the retention shank hooked on their pointer finger.
 
I put mine all the way back on my ring finger.
 
Anyone have a certain way they use the retention shank?

My dad who is in his sixties has been relocating rocks since he was a boy. With his style, which is his own, he swears by this. If the loop is on your index finger you can throw far. For closer targets the loop is placed on your middle finger and for close in, flat trajectory it's your ring finger. I don't know how much is perception and how much is science. I do believe that he's been throwing this way for so long that it works for him. I don't throw with the same consistency as my dad so I sometimes can't see where it makes as much of a difference to me.

I've tried every finger, a three finger loop over my first three fingers, and a wrist loop. I liked a middle finger loop the most, and I've had good experiences with the wrist loop. The others are okay, but not my preferred. The only way I won't use is a retention toggle- I'm probably just going to let go of the whole sling
 
There was a poll somewhere, and I recall middle finger being the most common, followed by the ring finger.  
 
Either way, any finger is correct and people tend to have different preferences. I also find that certain societies as a whole tend to use one method, rather than individuals having a choice. I recall on the Balearic isles, depending on where you live, you use one finger or the other (forget which, think it was index and middle). In South American examples I find a lot more slings with retention toggles (usually a ball or tassle of some sort) rather than loops. I recall someone stating that Tibetan slingers use wrist loops, however I've found more evidence for a finger loop?

I prefer to use a toggle a la manchega instead of any kind of finger loop. My newer slings aren't made with a finger loop at all. The retention side is longer than the release side and I wrap the retention side once around my palm. When I did use a finger loop I put it on my middle finger.

 I tend to use my ring finger for the retention loop because it gives me more spin on the projectile, which helps to stabilize the glandes that I favor.
 
Brian

Retention loop ring finger ... no particular reason other than it feels right.
 
or  
 
no retention loop ... extra long retention cord wrapped several times around the entire palm  
 
Still waffle on which style I like best loop .. or .. extra cord.

I started using the ring finger because I learned the figure 8 style from one of the  videos posted here and he placed it on his ring.  I've used it for baleric style, though reading this thread I might try switching it to my middle finger for a few shots to see how it feels.
 
Pikaru, any chance you could get video of your dad's style? (or your imitation of it) I'm always keen to learn from somebody who's been doing it for a long time  

Slip knot is not a bad idea. Makes it easy to accomidate gloves for cold weather slinging.