Website designed in the past 12-24 months
If you can tell your website is slightly outdated then so will your clients. A modern design with up to date technologies and graphics is the best way to scream at visitors you're an up to date and modern business!
Because Google want to improve the User Experience (UX) of sites found on their search engine, Google have changed the way they rank websites and now penalise those that aren't Mobile Friendly. If your site is not Mobile Friendly, Google are already warning users against visiting your website.
Professional Logo used
Have you had your logo designed or is it just plain text? Paying to have a unique logo created with your colours and possibly even company slogan is worth its weight in gold when it comes to brand power and recognition.
All products and services displayed
Your website is more than likely designed to promote your business online, so do you actually mention everything you do? Use your homepage to tell visitors everything you do and provide them with links on how to find out more.
Company Blog up to date
Blogging is great for keeping your content on your website relevant but it is also a great indicator for when a website has been left to rot. Blogs are a weekly thing, not yearly and need to be used wisely to show visitors how up to date your website is.
Social Media used
Social Media now has a direct affect on your Google rankings and the more likes and followers you can attract the higher your rankings. Use Social Media to engage with clients directly and show off how modern your design truly is as what modern site doesn't have Facebook and Twitter?