As you know from my posts, my kids are grown and I have worked with hundreds and hundreds of frustrated people, coaching parents and kids about this very issue.
Some of the things that I have tried successfully:
When my kids were around 6 and 10, I decided to teach money management skills. This lesson worked really well with managing TV- and the beginning of the play station nightmare.
On Sundays, I gave the kids each 4 envelopes. They were labeled: Weekly, Long Term Savings, Lunch $, and Charity.
The kids were given a set allowance(depending on age and need). My dad always said that allowance is what you are allowed and has nothing to do with chores. There was a bottom line amount that had to be placed in each envelope. The weekly money could be used to buy TV /Computer Time.
Certain shows cost more or less and some educational shows were free. The kids needed to learn how to budget their money and how they spent their time. The shows that I found absolutely horrid- obviously cost more.
I had a box, which they dropped the coins into. Of course I figured out how many hours I was allowing based on the amount of $. My kids felt in total charge of TV/Computer viewing. The benefits were amazing.
As to the other envelopes, my kids learned lots of lessons about putting off what they really wanted, making choices that impacted their lives.(ie. I let my son borrow from one envelope to get something he wanted sooner, with the stipulation that he had to put an IOU in the envelope. He later informed me that he was never doing that again! ( I believe that he borrowed $ from Weekly to buy a video game — there wasn’t any $ left to play the game!!)
As the kids got older, we just had a bottom line rule. No TV/Computer Sunday- Thurs- during the school year except if parents offered. They weren’t very happy about this but years of making choices had made them fairly discriminating TV viewers anyway.
Over the years, as I approached my kids with a new idea, they would usually be receptive. They got it that I was trying to give them some control over their lives and they also knew that they were my test subjects for ideas I would pass along to my clients!