I don’t have one, but I read a lot of them on a daily basis (mostly decorating blogs) and I think one of the most important things is to post something new and something that your readers can learn from. I think having pictures is also very important, since it’s such a nice break from text to have pictures thrown in. Being a good photographer can also get you far – I read some blogs that are often mostly pictures with a few sentences thrown in – the writer doesn’t have to work too hard on copy because the pictures kind of speak for themselves.
I do actually have a personal blog where I sometimes update about my life, but it’s private and limited to a few old friends who live far away. If your goal is to just start a personal blog to talk about your daily life, then trying to get some friends involved is a great way to get followers. If you want something public that many people will read, then I think, like I said above, that you need to think hard about each post and make sure there’s something new, interesting, or educational that will make people want to read.