Here is how I tie my ostrich scud:
Orange or ginger scuds are tied on a standard scud hook, #12-#20.
Olive, gray, and tan are all tied on a wet/nymph sproat hook with a Kirby bend (Kirby bend is where you twist the hook point sideways just a bit).
I weight them with the smallest lead wire I can find, but I don't wrap it around the hook. I tie a small segment of lead to the hook lying flat against the shank. I tie in the ostrich herls (2-3) and silver or copper wire, palmer the herl and counter wrap the wire, and tie off.
Now, here's the secret: light a candle and slowly move the finished fly close to the flame, back first. The result is the herl on the scud's back will burn away, leaving a nice looking segmented back. I hold the fly in my fingers to protect the herl on the bottom of the fly from burning.
Note: Do the last step slowly, or you'll wind up with little black bumps on the back of your scuds from trying to burn it too fast.
That, my friends, will make one killer scud.