It's old but it's gold! Optimise your website for desktop, mobile and tablet. We have said it before and we keep on saying it because we still see websites for all or any size business that aren't mobile ready?
Now if it's budget that is in your way, you invested in a website years ago and haven't been able to afford an upgrade since, panic not, just make it a goal in 2019 to get your site up to speed!
Many websites are made for mobile first in 2018 and it won't be different in 2019, users in some industries and for some products are mobile only, you may be a gym or selling products to teens; they will be visiting you on their phone.