Making your own templates has the advantage that you can develop a relationship with the quilt you have envisaged. It also gives the option of changing your mind during the making and assembling process. It cannot be taken for granted that every quilter knows how it is done in a contemporary way: using graph paper, photocopying and drawing lines for geo-isometric designs. During the golden years of quilt making a prerequisite was making your own templates and that was incorporated in your sampler. Nowadays quick and easy methods plus detailed construction techniques forced people into 100% copied quilts. Recently partial copying and original designing are promoted with back to basics with more challenging new ideas. Categorize the basic block and quilt layout and decide on a row count necessary for triangular characters.
Paper templates are needed for master patterns for a specific block or quilt. P This is all explained in detail in my book, Quilt Potpourri. Good luck and may your next quilt be your best quilt ever.