I think this is not a new tip, but I actually had very good result with this trick, so I want to record that here. The tip is pretty easy. Just add some senolina (durum) flour to the pasta water.

When pasta water boils, add 1/4 tea spoon of semolina flour to the pasta water per a liter (1 QT), then it makes pretty starchy pasta water. This is especially good if I cook some oil-based or cheese-bases pasta like Aglio e olio or Cacio e pepe.

Of course, this tip is not required for good bronze-cut pasta, but this is especially helpful for cheap or mid-tier pasta.