It depends where you move to, and how far away it is from where you currently live. I'll tell you what some people I know did, and then let you decide!
I live in London and one of my housemates decided to return home to Birmingham. Finding a job was the easy part. You just look in the same way you normally would, and then, as the train between London and Birmingham doesn't take very long, he was easily able to travel there every time he had an interview. Finding somewhere to live was harder. As long as you have internet access, then you can easily see what is available and set up viewings. What he would do is then travel up at the weekend and view places. What made it hard was that if you find a house and then it falls through, what happens? If you're in your home town then you have friends or relatives to stay with, as he did. But you need to think about what you would do if you are moving to a town where you don't know anyone.
Then, a friend of mine moved from Cambridge to London. She went for the "save, move, and then find a job" option. There were no problems at all, but the thing is, she is an accountant so a) had plenty of money saved and b) knew that once she got here, she would find a job quickly and easily.
If I were you, I'd go for the second option. BUT it really depends on what you do for a living. I would advise it only if you're going to an area where you will find a job quickly and easily (e.g. if you were coming to London, you could walk into a secretarial job the day that you got here), or if you're really not fussy about what you're going to do and will take the first job that you're offered.
One final piece of advice - don't stress about it! The UK is full of immigrants who just turned up with nowhere to live and no job, and manage just fine (I'm one of them - I'm from New Zealand). So if you do just turn up in a strange area, remember that it won't take long to sort yourself out at all.