Lizziegorge:
I'm just a parent and worse yet middle class academic - but it seems to me that control/ behaviour in classroom is all about who's boss. You've got to be boss.
You're top dog and they're your pack. What you say goes.
However - it's easy to say possibly harder to work out in practice:
Some resources:
TES behaviour advice here: www.tes.co.uk/article.aspx?storyCode=6175180
my brother teaches in US and finds Class Dojo brilliant for his 10/11 year olds: www.classdojo.com/en-GB - he uses it by having them agree as a class in advance what is good behavior and what is bad behavior for a task/ field trip in advance. The scores are reported to their parents (which terrifies the kids) - and if they all do well - there reward is things like: longer break/ class outside/ Popsicle surprise (if they've been great - my brother buys his class posicles in the spring/ summer months when its good weather - he says it costs him $10-$12 but they worship him for it - so its money well spent)
REWARD THE WELL BEHAVED. Too often teachers focus all attention on those misbehaving leaving the well behaved to it. Flip your behaviour so that the well behaved get your attention (those sitting nicely/ those raising their hands/ those who have been working hard at their table) and those who have been wandering about/ chatting/ messing about are told you'll see to them last, because clearly they're not interested in learning.
TALK TO THE PARENTS - Yes spoiled middle class kids who are used to getting their way are awful (it is a stereotype but it does exist) - but most parents would be mortified to find out their children are behaving badly. And most precious middle class parents want their children to be well educated. So hit them where it hurts: Ye olde - Johnny is clearly bright but I'm afraid he's expending all his energy on being the class clown rather than his work. I'm very concerned because if he would concentrate he'd probably be a sure fire thing for XXXX independent or the 11+, etc... I've tried to manage it in class and of course will continue - but it would really help if you could reinforce with him how important it is to settle down to work during key times like literacy/ numeracy hour. He's really holding himself back with his behavior.
Finally - consider sanction. If you have children who are constantly being sent out of class for poor behavior, you've spoken to the parents, etc... - then maybe it's time to withhold their right to the 'perks' of primary school: school trips/ special assemblies/ recess/ etc... Maybe it's time to assign extra homework - which if not complete will have to be done in the HT's/ Deputy HT's office before rejoining class. Warn the parents this is the final straw before exclusion - but basically - the reward for conforming is return to access to the 'fun bits'.
HTH