Difficulty rises through the week
The NYT Crossword gets harder as the week goes on. Monday is the most accessible, Tuesday through Thursday ramp up, Friday and Saturday are the toughest (and themeless), and the Sunday puzzle is larger but roughly Thursday-level in difficulty. Knowing which day you’re solving tells you how much misdirection to expect before you start.
If you’re building the habit, solve Monday–Wednesday consistently first; the early-week grids teach the recurring vocabulary you’ll need later.