Starting is much much much harder than continuing. If you've made the decision to write, it's better to post something, anything, to get on a roll. For example, today I posted a book review[1] just to keep on a writing stretch. It's not my finest work, but it's enough to keep me going.
I don't have to keep going, I want to keep going. Writing is something that I've decided to try to get better at and every article I write gets me incrementally better.
Re: siblings and increasing writing skill: there are too many blogs. Try writing in private and for literary (i.e. non-tech) audiences. You'll have better chances of focusing on the actual writing, you'll be able to branch out, you might get feedback on your writing.
[1]: http://bugsplat.info/2013-05-25-book-review-tubes-a-journey-...