Write something useful for your readers. Share a relevant piece of information, an event update or a hack that makes a task simpler
KISS - Keep it simple stupid. Always keep your blog simple, organizes upto the point. Do not over-flood with unnecessary posts or irrelevant images and keep your content straight-forward.
Don't just type, talk to your audience. Blogging is way big a market on internet and people will like you if you do more than just providing information. Suggest, express, appreciate, criticize and have an opinion to build a relativity to a like minded audience. Make them feel that their visit to your blog matters to you.