Hi Mark
Tapering tangs is a little tricking and even harder to explain.
Get yourself the book on how to make knives by Barney and Loveless.It is available from Krause publications ,the folks that publish Blade Magazine.
This a excellent guide for the beginner knife maker.It covers three methods of knife making,Stock removal including tapered tangs in a complete knife making shop,Forging and making one from bar stock using tools you already have at home.
Good book I always recommend this book to beginers.
Murray