Always best to go through a solcitor IMHO, they can point out the pitfalls and you will get a professional job done. I think people are more likely to contest a will if it's a 'home made' version - not meaning to be disrespectful to your nearest and dearest here!
I got mine done through the union I belong to (UNISON) although it was a few years ago now, it didn't cost me anything, might be worth enquiring if you belong to a union. I'd advise anyone whatever age to make a will, I was 37 when I did mine. It's just nice to know that all your affairs are in order and my daughters will not have to go through what I did when my Dad died. He didn't make a will, and although his estate was straightforward, it still took almost 2 years to sort out.