Some important questions to ask are what would they say their best and worst qualities are? Ask them about their last position and why they are leaving. This is a great question to find out about a potential employees past work history. Ask about their ambitions and where they will see themselves if they joined the team. What kind of role do they play in their friendship group? You can really learn a lot about your potential staff member by listening to their experiences and self-statements.
Don’t be unreasonable about your demands if you have been scorned before and just want the best for your business. However, if your gut has good feelings for someone but they aren't incredibly up to scratch on past experience, maybe give them a chance. The most successful people just need that exact thing to get them going- A CHANCE!
Good luck x