I knock one corner back into it's self. Then flip on the side and forge the bulge down. Then back to the corner and to the side. After a few min you have a point that is close to what you want your preform to be. But I will admit it's faster to nip the corner off with a hot cut on the anvil. Another easy way is to clamp it in the post vise and go at the corners with the hammer and knock them back into the stock. Another way that's way over the top is to notch a v in the front then heat and flux and forge weld the corners down closing the V gap. This is much more common when working with Damascus as it creates a pleasing end to the pattern instead of it just running off the end of the blade.
