"This year I want us to make the sukkah with real hidur mitzvah." (Glinert)

"I wish your son could put a bit more hidur mitzvah into the way he cleans his teeth." (Glinert)

"It may interest you to know that Rav Ernest Weill, who was an important Orthodox “Grand Rabbin” in Alsace in the first half of the 20th century and who penned a French-language “Choul’hâne Aroukh abrégé”, wrote that electric lights were actually a hiddur mitsva for shabbat and chanukka candles because their light is so much more beautiful." (source)

"The musical beautification of sacred texts also speaks to the issue of hidur mitsvah, the adornment of a sacred obligation, as a necessity for making prayer work" (source)