Announce the post in the tweet
It's a good idea to announce the tweet with something like "new blog post". Stats have shown that this phrase helps increase the number of clicks the link gets.
The body of the tweet will be the title of your blog post. So, you should already have something clear and compelling here. But there's no reason why you shouldn't rewrite it to make it punchier and pithier for Twitter.
Use good hashtags
Make sure you include appropriate hash tags at the end of the tweet, although you don't want to use too many. Apart form anything else you want to leave enough free space so that the tweet can be retweeted by others in full.
Speaking of hash tags: I've found that if the blog post has photographs and I include the hash tag #photos, I tend to get a greater number of clicks than if I don't.
Makes sense, of course. People do love pictures after all. And it's yet another reason to start including them in blog posts if and when they are appropriate.
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