URL is one of important point to impress search engines. Having a good URL and URL structure is essential to support the Search Engine Optimization (SEO).
The first thing you want to do is keeping all the URLs short. Just like your domain. Short enough to be typed manually in the address bar. Use simplified permalink if you have a dynamically updated site.
And like any other SEO strategy, use keywords. Make sure we include our chosen keyword in our URL structure. For example, you run a casual clothing online store and you sell t-shirts, jeans, shoes for both men and women. The structure should be:
Simple tips, but can help your site appear higher in search result.