Spend time discussing with your DJ how they are going to customize the music experience for you including their familiarity with current popular hits in preferred music styles.
Ask them if they can offer a customized song list, including special songs important to the bride and groom, or offering song requests to guests.
Look for a DJ who can provide more than one set up, so they don't have to transition their equipment during the cocktail hour. Speak with them about a backup plan if one system fails.
Look for a DJ who can provide a lapel mic for the officiate during the ceremony and a handheld mic for the toasts. Be comfortable asking about all the services they provide, how many hours are included in your package, and if they have played at the venue before.
Some DJs even provide additional services such as special lighting and effects, video screens, or a photo booth. You will want a DJ that is skilled in blending songs for a seamless transition and knows how to get the crowd excited enough to encourage them to dance.
Look for a DJ who is flexible and willing to listen to your ideas. The good ones are worth every penny you put into them."