I will warn, "Out of the lane", "Hands off", and "Watch the boundary" (aggressive throwin defender, additional, "Pane of glass," to a middle school player), but there is a limit to how long I will warn, longer time for lower levels, less time for upper levels.
Occasionally a, "Cut it out", to two post players fighting for position, trying to avoid calling a double foul.
I may warn, "Let it hit", to players behind the free thrower who look like they want to sprint in early for a rebound (like a runner at the starting line of a race).
Knowing that there will be a "deliberate" clock stopping foul at the end of the game, I will often tell the defense to, "Go for the ball", sometimes to the players right as they come out of the huddle after the first timeout warning buzzer.
Middle school early season games, I will instruct players on first free throw of the game, "Rebounders on lane - on the release. Shooter - let it hit. Players behind arc - let it hit", loud enough and deliberate enough so that players on both benches can hear me and see me. Only middle schools, only very early in the season, and only early in the game, not more than once a game (many middle school coaches are unsure of the rule).
Of course, according to proper mechanics, "Designated spot", or, "Run the endline", with proper signals, for all backcourt endlne throwins.
As usual, check your local listings.
For the young'uns: