Lets with what a strategy is in case people are unclear on what that is. A strategy is a method or plan chosen to bring about a desired future, such as achievement of a goal or solution to a problem. To simplify this we are figuring out how to get from point A to point B and how you are going to do that. That means what competencies you need, what tools you need in order to get the job done.
Lets get back to what Digital Strategy is now. Digital strategy is the manner in which you would achieve a goal using your website, campaigns, social media marketing, internet marketing, SEO and a variety of other things that would be dont using cloud and internet applications.
So where to begin? You can use the example of selling your services or a product you need a website obviously and you would want it to be responsive. In order to promote your website you would want to implement some techniques such as SEO, utilizing social media, collecting an emails list. These are actions you need to take as part of your strategy to meet the goals.
The goal isn’t to to give an entire digital strategy here but at least to break down what it is in order to simplify and help people understand what this is and why you need it. Hope this helps.