and there's the problem in a nutshell, making up our own lotg/rules can, i would suggest, only ever increase and never decrease the level of inconsistency from referee to referee - and i'm as guilty as pretty well everyone else on that score, i would imagine.
f.a. laws for mini soccer, u7 and u8, do say that 'referees should also recognise their role is to facilitate learning of the players, for example, allow young children to take a second attempt at a throw-in if the first is not within the Laws'.
even the guys who ran my training course, last january, talked generally about making allowances for younger children, e.g. blues v reds (under whatever), blues 10-0 down, a minute to go and a blues defender deliberately handles the ball on the line to prevent an eleventh goal, do you send him off?
taking your example of 'second chance at a foul throw', best advice i've had to date is to take my lead in whether to make this 'decision' or not, pre-match, from the respective team managers
last month, i was refereeing a sussex cup quarter final, u12's, blues v reds. first throw in of the game, by reds, was a foul throw. i blew for it and asked the player to retake, explaining what he had done wrong, imho, as has generally been my habit to date where u11's and u12's were concerned - (until, of course, the same player has done it for a second, third or fourth time and i finally get fed-up and award the throw the other way). oh the inconsistency
As he took it again, shout from the opposite touchline, from the blue team manager, 'that should be our throw, ref' - aargh, he's right, what to do?
i held up the throw, trotted over to the blue team manager and explained that part of my role was facilitating learning, same for both teams, blah, blah, blah etc.
blue team manager accepted what i was saying but agreed to disagree. fair enough. thankfully, amazingly, whatever, that was the only foul throw decision i had to make during the whole match. there clearly is a god, at least where referees are concerned.
i put this scenario to my refs course trainer, as i do with several first time 'issues' and his words of wisdom, on this occasion, were to ask the managers how they wanted me to handle throw-ins, ahead of the game, retakes or not and,unless there was consensus on retakes, foul throws would be penalised according to the lotg. is this right?, is this wrong? - well, it's certainly an improvement on making a unilateral decision to ignore the lotg, imho.
having said that, personally i would never offer managers a choice where issuing cards was concerned, i'm not sure that any referee would take that step, so this method doesn't resolve the issue raised by the 'yellow at one age level, talking to at another' poster.
the joy and the complexity of refereeing, in a rather lengthy nutshell