We have a lovely 19 year old DS. Not had any problems at all. We've led by example from the day he was born. He's never seen us arguing or rowing or banging doors, etc.
Ours is a "calm" house whatever is going on. We've treated him as an "adult" from when he could first walk and talk, always included him in our family/home/holiday conversations and planning, even when he was so small he had nothing tangible to add.
When he's done anything "wrong" in our eyes, we don't hit out or blow up at him - everything we do and how we react is carefully considered. When he was playing Club Penguin online when he was around 8/9 years old, I looked over his shoulder and saw he'd used a pretty nasty saying (slangy/obscene) on the game - there's no way he had the faintest idea what it meant - he'd just seen someone else use it and was copying it. We had "the conversation" the next day about what was and wasn't acceptable re swear words/obscenities etc and yes, he hadn't a clue he shouldn't have used it, and to this day, 10 years on, he's never used even a modest obscene/swear word in our presence (pretty sure he'll say things when with his friends now, but he knows not to do it in front of us or our family).
Yes, too, re gaming etc. We gave him notice it's time to stop, to finish the game he's in. If it was a long game, he'd tell us, and that's fine. No tantrums or arguments or us pulling the plug out mid game.
We also manage his expectations. When it comes to Christmas and Birthday, sometimes he gets something big/expensive, other times it's just a few token gifts. All depends on what he needs at the time. We discuss it with him. We'd never "surprise" him with a new Xbox - he'd be part of the discussion process, from months ahead, considering what he needed etc and it would all be planned. Of course, they'd be surprises too, but they'd be smaller and less critical.