Expectation. Watch any tv game, even with the fifa lino standing where the ball goes out.
esp in defensive areas, esp even more so if they steal distance up the park,but are clearly going to throw the ball back, play on, Let your game flow.
Do not be exact publically with your intended position of restart. If you are, and the throw is not taken from the exact place you instructed, you have dug a hole for yourself, if you let it go you now look weak, if you penalise it, you now have an unwanted awkward remainder of match organising throw in restarts
say the ball goes out at halfway, prompt the player say, 3/4 yards before he gets to halfway, that way, even if he takes an extra few yards, he only be 3/4 yards from the correct place,
be proactive, use voice, "thats fine thanks", when he there or there abouts
if its clear he running too far with ball , whistle, " back thanks"
attacking throws you might wish to reduced the flexibility,
if your games going well, play on.
use more exact location when you need establish control.
if your main focus in a game is throw in location, you are overlooking plenty bigger issues
If the players are annoyed in your game, it might ( might) be possible your approach is a surprise? Not really needing surprises to control a game