I'm a Brit that moved over here 12 years ago and i've had 2 good mates move to Aus and another to NZ, best advice i can offer is think about why your doing it.
All 3 have moved back to the UK, but to be honest their goals and expectations were totally unrealistic.
They were expecting some sort of paradise where everything was better and they were very quickly disappointed.
The 2 in Aus said that many of locals were not interested in getting to know poms and although meant in jest they got very tired of the pom jokes and being poked fun at.
They also said they felt there was absolutely no culture over there apart from going out and getting drunk.
Being here for 12 years i've also seen many many ex-pats come and go and i recon i can tell the ones that aren't going to last very quickly now within a few mins.
I think if you go over with the mindset that it's going to be a experience and an adventure you'll stand a better chance.
You should also expect just as many problems as you experience in the UK, they'll just be different problems.
People tend to emigrate and have a honeymoon period of a few months, this is mainly because their outlook has changed for this period.
They tend to be more open and don't look for problems, after a few months though their personality tends to stray back into how they were before they left.
So they end up being the same person but in a different location.
If that person is moaner then they'll just become a moaner with a different view.
So don't expect to move thinking that it will give you more energy or it will jump start you to do things you don't currently do.
A lot of that is pretty true....
The number of UK folk that shift over here without ever having been here before is quite amazing.... Likewise the number that pull the pin within the first 2 years is also quite high...
Folks go back for lots of reasons. But fundamentally you need to know what you're getting into before you shift anywhere Canada, Aussie, NZ.
You also need to adjust and accept the culture you are in... a lot of expat Brits here in Nz I know struggle with that, constantly comparing stuff back to the Uk really does you no good in the long term...