I've only got one toddler but this is what has helped me. DEFINITELY get some 'me' time as a previous poster said. And yes, you have to schedule it or it won't happen. I put DD into care for 3 hours on Friday morning and even that short amount of time once a week works wonders on recharging my batteries.

As far as bad behaviour/tanties go, I give lots of commentary about what we're going to do next. "OK, we're going to eat lunch DD and then it's sleepy time." I literally do that for 10 mins beforehand over and over again. Same if I want to take her out for a walk, "OK DD, nearly time to stop watching that DVD, we're going for a walk. We're going to put your shoes and socks on and then we're going for a walk." I say it many, many times so it doesn't come as a shock to her.

If I let her, she would literally wash her hands for half an hour because she loves water. So I have to give her warning, "OK DD, we're going to switch the tap off after three."

It took a couple of weeks of doing that but it's reduced the tantrums no end.