The first thing you have to remember is that people aren't necessarily visiting your blog out of habit. They have to be attracted there from many different sources on the Internet. At this point, the only tool you have to attract them with is the blog title, and also increasingly a short summary paragraph. Both of these are free from any formatting, and therefore must rely on the content to attract attention.
The title is probably one of the most under-rated pieces of real-estate you have complete control over. The title finds itself everywhere, in search results, aggregator pages, email alerts, RSS feeds, side bars - everywhere! So making sure your title is strong enough to warrant further investigation is key.
The other literay weapon you have in your arsenal, is the blog summary. Some blog tools/providers don't provide for a separate summary and this is very poor, as you are relying on search engines etc to guess a summary by extracting the first few hundred characters of your entry. This can be horrendously misleading. Take control of this area and write your own.
The blog summary is utilised by search engines to give a little bit of feedback to the user as to what the page they have just found in a search is all about. The summary is also used by aggregators as the majority of RSS output utilises only the summary. In addition, the summary is used throughout your own blog as people surf around your blog looking for interesting pieces. It is therefore crucial you take your time and provide a meaningful summary for your entry that will help promote and sell your blog piece.
The summary and title are both used by some of the search engines to rank you in their results. If your title, summary and entry all look related then this will increase your page ranking every so slightly. The rules on how search engines rank pages are always being fine tuned and there isn't one magic bullet in this respect, but you can help yourself, by make sure they all make sense, and you aren't deceiving your audience with false promises.
It generally only takes one good entry for a reader to make a decision on whether or not they wish to return to your blog, or even better, sign-up to your mailing list to be alerted of future publications.
Don't let the title and summary go to waste, they are your only hook to get the outside world into your blog.