When blogging, you're doubtlessly going to want to use some images because if you don't, it will be worse for customers and worse for SEO. Images help to break up a piece of content and make it more digestible, but one thing which you should always try to do (and which a lot of people do not do) is include captions on your images.
So what's the benefit of adding captions? Well, it does a lot from an audience perspective. Are you having to use stock photos because you can't afford to commission or buy your own? Well, then you could use captions to make light of that fact, changing you from a small business pathetically trying to look bigger, to a small business with a fun sense of humour. They're also useful for explaining what is happening in a picture, or what is shown, because these things won't always be clear. But beyond just boosting your customers' enjoyment, you can also gain some SEO benefits by including keywords which will compliment and the piece nicely. Having said that, don't use this as an opportunity for keyword stuffing, as this is never going to be very beneficial.
So I hope this gives you a good idea of one thing you can be doing to help make your blog posts even more effective. One thing that's always important to remember is that the more you try to make things easier for your customers, the better optimised for search engines your website will be and the better the SEO, the more people will find you! Blogging is something which is hugely valuable for a whole range of reasons and the better your blogging is, the more effective it will be. Keeping these things in mind could be a great benefit to your eCommerce website.