Slo-MO. The Modus Operandi of today's puzzle was to have each theme answer be a two-word phrase where the first word begins with M and the second word begins with O. Working this puzzle, however, was anything but Slow.
17-Across. * Consider carefully: MEDITATE ON.
21-Across. * Transformative beauty treatment: MAKE OVER.
54-Across. * Talk back (to): MOUTH OFF
59-Across. * Divvy up: MEASURE OUT.
And the unifier:
36-Across. Plan of action, as "initially" found in the answers to the starred clues?: MODUS OPERANDI. The phrase Modus Operandi is a Latin phrase meaning Method of Operation. I would narrow the definition provided in the clue to mean an established habit of working. It is frequently in the context of a business or criminal endeavor. Modus Operandi, or MO, is often used in detective/cop television shows.
Across:
1. Goal of much medical research: CURE.
5. Like a baby with pudding, probably: MESSY.
10. Floor model, e.g.: DEMO.
14. "That'll be the day!": AS IF.
15. Jazz great Earl "__" Hines: FATHA. Earl Kenneth Hines (Dec. 28, 1903 ~ Apr. 22, 1983) was an American jazz pianist and bandleader. He was considered one of the most influential figures in the development of jazz piano. He apparently earned his nickname "fatha" after giving a drunken announcer some "fatherly" advice to limit his drinking. [Name # 1.]
16. Woeful word: ALAS.
19. Home in the sticks: NEST. Cute clue.
20. Fluster: ADDLE.
23. Fancy timepieces: ROLEXES.
26. Luthor of DC Comics: LEX. He is the supervillain and archival of Superman. His full name is Alexander Joseph Luther. [Name # 2, fictional.]
27. Stand-up comedian Shaffir: ARI. I am not familiar with Ari David Shaffir (b. Feb. 12, 1974). [Name # 3.]
28. Undivided: ONE.
29. Removes soap from: RINSES.
31. Tic-__-toe: TAC.
32. Maytag sister brand: AMANA. How the two companies are related. [Name adjacent.]
34. Tusks, e.g.: TEETH.
40. Writer Sir Arthur __ Doyle: CONAN. Sir Arthur Ignatius Conan Doyle (May 22, 1859 ~ July 7, 1930) is best known for being the creator of Sherlock Holmes. Doyle tried to kill Sherlock Holmes, but his readers protested so much that Holmes was resurrected. [Name # 4.]
41. Still-life pitchers: EWERs.
42. GOP gp.: RNC.
43. Bearded spring blooms: IRISES. Vincent van Gogh (Mar. 30, 1853 ~ July 29, 1890) was known for his numerous paintings of Irises. If you are ever in Amsterdam, a visit to the Van Gogh Museum is well worth a visit.
46. Many an email attachment: PDF. Portable Document Format.
49. Earlier: AGO.
50. Intentionally mislead: CON.
51. "Don't let that woman get away!": STOP HER!
57. Garlicky mayonnaise: AIOLI. This vowel-rich condiment is fast becoming a crossword staple.
58. Angry: SORE.
62. Rae of "Insecure": ISSA. Issa Rae (née Jo-Issa Rae Diop; b. Jan. 12, 1985) makes frequent appearances in the crossword puzzles. She had her own television show, Insecure, which ran from 2026 until 2021. [Name # 5.]
63. Industry honcho: BARON.
64. Surrender, as territory: CEDE.
65. __-do-well: NE'ER.
66. "You __ sweet!": ARE SO.
67. Potato buds: EYES.
Down:
1. Chevrolet that will be discontinued in 2024: CAMARO. The Camaro was first sold in 1966. It had a long run. [Name adjacent.]
2. Applied to: USED ON.
3. Brain-breaking question: RIDDLE. Here's an ancient riddle that dates back to 18th Century BCE in Samaria: There is a house. One enters blind and comes out seeing. What is it? For the answer, you must read this article.
4. Paperless option for taxpayers: E-FILE. We just had our annual visit with our CPA.
5. Curator's deg.: MFA. Master of Fine Arts.
6. Take in: EAT.
7. Women in __: educational advocacy org.: Science, Technology, Engineering and Mathematics.
8. Sandbars: SHOALS. This makes me think of the Isle of Shoals, which are a group of small islands and tidal ledges situated approximately 6 miles off the east coast of the United States that straddle the border of the states of Maine and New Hampshire. Writer Anita Shreve (Oct. 7, 1946 ~ Mar. 29, 2018) wrote The Weight of Water, a historical novel about a murder that takes place on the Isle of Shoals
9. Big Apple MLB player: YANKEE.
10. Paul of "The Batman": DANO. Paul Dano (né Paul Franklin Dano; June 19, 1984) portrayed the Riddler in the 2022 version of Batman. [Name # 6.]
11. Like some beachside homes: ELEVATED.
12. GranTurismo automaker: MASERATI. Maserati is an Italian manufacturer. The company was established in December 1914 in Bologna, Italy. [Name adjacent.]
13. Bird with a powerful kick: OSTRICH.
18. __-Mex cuisine: TEX.
22. Celeb who's no longer in the limelight: EX-STAR.
24. Important ages: ERAs. Taylor Swift (née Taylor Alison Swift; b. Dec. 13, 1989) is on her Eras Tour.
25. Chinese: Pref.: SINO-.
30. Kitten-lifting spots: NAPES.
32. Oral health org.: ADA. American Dental Association.
33. German city that hosted the 1972 Summer Olympics: MUNICH. The 1972 summer Olympics were overshadowed by the massacre of 11 Israeli athletes.
35. Napkin corners?: ENs. I suppose this means that the word Napkin begins and ends with the letter "N". Rather like last Friday's clue about Label Edges = ELs. I didn't care for that clue, either.
36. Ferretlike carnivore: MONGOOSE.
37. Proceeding as planned: ON COURSE.
38. Lambs' moms: EWEs.
39. Take a break: REST.
40. Adds to an already full suitcase, say: CRAMS IN.
44. Saucer-shaped vacuum: ROOMBA.
45. With trepidation: IN FEAR.
46. "Nuts!": PHOOEY.
47. Intentionally mislead: DELUDE.
48. Steak __: bistro dish: FRITES.
52. Rowboat blade: OAR.
53. Component: PIECE.
55. Run like heck: TEAR.
56. Cab charge: FARE.
60. Letters sent in emergencies: SOS.
61. Game with colorful cards: UNO. This game has become a crossword staple.
Here's the Grid: