very definiately with DS1 who is 3; if I get cross he gets worse,
if I play down his bad behaviour and give him positive attention the difference is amazing. Time out tends to make him worse, much better to get to his level, explain why he should stop what he is doing and then ignore him. If continues threaten a sanction (eg to remove toy) and then if continues will little fuss remove toy.
But far more importantly praise the good. If leaving the house is a flash point, talk the dc and say we all fight lets make it better, (and then look at things you can do to ease the tension eg -sort out bags before you start getting kids ready. Then if he does leave the house nicely give him a sticker or lots of praise.
I also think consitency is massively important so if you and your Dh are doing things differently your kids will be confused and play up.
Give warnings about things that are going to happen eg - we'll watch the end of this programme then lets turn it off, then as it ends say 'the programmes ending in a minute' then when it ends say 'who wants to turn it off' (they actually fight to do this in our house...the same kids baying to have it on 10 mins earlier )
The warning thing works for everything; tea time (and we're having..), it makes them feel like they have some control as they know what is coming next. I would hate for someone to say shoes on we're off out now with no prior warning.
Also your DH needs to sort out his anger, it can be very frightening for a small child. It is like that to you?
I second the book 'how to talk'
and parenting classes can be really good.
hope things get better