>>>Has anyone used cotter pins when tying articulated flies in place of the front cut off hook or a Waddington?

I certainly have. Here are some links (that I hope are OK to post):

http://speypages.com/speyclave/showt...ht=cotter+pins

http://speypages.com/speyclave/showt...ht=cotter+pins

That forum has a search function for more..

>>>If so any special considerations?

I had the same concern others expressed regarding the "D" profile so I intentionally snagged a few flies on the bottom (that's my story and I'm stickin to it!!). Every time I would pull like crazy and when something finally let go, it was the loop I put the stinger hook in. (I use superbraid fishing line for the loop). I would have maimed any fish long before that.. so from my experience, the "D" loop thing isn't a big deal.

Balance the weight/size of the cotter pin with what kind of sink rate you want and size of the fly (of course).

I have heard that some guys tie on stainless cotter pins. I don't. I have a box I got for cheap at a discount tool place. I can fish big heavy flies close to the bottom without worries that way.

The pins I have all have the tip of one "leg" a bit longer than the other and that's the little nub I put in the vice. It's not a lot to hold onto, esp if you are really going to pull hard on the thread as you tie.

Hope that helps..

Scott