The best (and only) place to start with digital engagement – as with any form of engagement – is with your purpose. Why do you want to involve the public? What impact are you looking to achieve?
Your answers to these questions should shape everything else that you decide, from who you seek to involve, to how you try to engage them. For example, you might be looking to the public to help propose ideas for tackling an issue; weigh up the advantages and disadvantages of different courses of action; review and improve your plans; take action or something else entirely.
Your specific purposes might dictate that you need to engage a specific group or community, a representative cross-section of society, or anyone who’s interested and/or has something to offer. They will also determine the form that your engagement should take and therefore the sorts of tools and techniques that you’ll need to use.
As with any form of participation, it is important to consider accessibility and inclusion as part of your digital engagement planning. Do your intended participants have good quality internet connections? What devices, if any, do they have access to and use regularly (e.g. computers, tablets, smartphones)? How comfortable are they with using technology and different types of online platform? The answers to all of these questions will have implications for the tools you might choose, how you use them and what sort of support you provide to people to participate.