Advisory boards and their relationship with the entrepreneurs are subjective to what you need to fill gaps in either your expertise or company. If you need legal support, having a lawyer on your advisory team would be a great asset; if you need someone with the business connections than choosing someone who has a strong network can really help make your business. Because they are not an official part of the company, the relationship is key!
Choosing the right advisory board members is important! Make sure your advisors are people who will tell you the truth, it doesn't benefit your business to have things sugar-coated or backed with assumptions and not facts. You should also be choosing people who can help your business succeed in the market in 2019; that means looking for people who understand your industry and the current market.
When it comes to advisory boards you have to ensure that you manage that the relationship so it best fits what you need from them. That comes down to managing expectations of their involvement and making sure the relationship is beneficial rather than just making more work for the entrepreneur. Make it clear how you want them involved and where you will need their support.