A quilt of squares on point is really just rows of squares together. Start with one square in the corner on the bias, three in the next row, then five, seven, nine, etc until your quilt is wide enough. Then add more rows of that last number until it is long enough. Next, start adding shorter rows until you get to the that last row which will be one square. Now pick up a row of squares on the diagonal and sew them together.
After all the rows have been sewn, make the side triangles by cutting a large enough square into four from corner to corner both ways. Make the corners with two squares cut on the diagonal. This way, all bias edges are sewn onto the straight edges of the other squares and only straight grain is on the edge of the quilt.
Sew the triangles onto the rows where they need to be and then you can sew all those rows together in the correct order. The two end "one square rows" will have three triangles sewn to it.
I try to make my triangles a little larger so that there is a little "float". Then I put my ruler on the points of edge squares and cut about one half inch from the points. That way you have a little wiggle room so you don't cut off points.