There are many ways to make HSTs and some are really bad. Beware of methods that leave bias edges on the outer sides. An example of this is the sewing of a 1/4 in around the outside of a large square to make many triangles at a time.
If you sew an x on a large square to make 8 at a time you will not have any bias edges. But these methods do require squaring up over sized HSTs. If you prefer to square up I recommend Quilt In A Days triangle square up ruler that uses one cut to square up.
I bought the Triangulations cd and am not impressed. I do not like using paper to tear off. It does make exact size triangles. It was expensive and you can draw your own paper patterns without the cost of $22 dollars.
I have a set of Ta Da interfaced triangles this leaves interfacing inside the triangles. Great to use as a pattern for exact size paper triangles.
After trying many different ways for many years I recommend the Quilt in a Day way over all the others. Your triangles come out perfect every time with just one investment for the triangle square up ruler. It is also faster and easier to do. No paper to tear off and squareing up is just one cut.
By squaring up you know they will be perfect every time and you make 8 at a time.