nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpqecm04chqxjk8m3xvm7wu92kf2t0fw5cur277wy6acp88gh35wjssqhwxfp (nprofile…wxfp) The term defines itself pretty well. From a practical perspective, the most important factor for me is which glyphs feed into most others in terms of shapes, details, and proportions. Those are sometimes frequent letters, but not always.
That said, when I am working on Indic scripts with Fiona Ross she likes us to start with the letter ka because it is considered auspicious.