Look into his/her online portfolio before meeting in person. Photographers with no portfolio should not be considered. Is this work recent or old dated? The body of work is consistent, lighting seems right, posing, desire to move around and find new places when taking the pictures, creativity?
Check his/her online presence: look at the social media, specially Facebook, Instagram and Pinterest. Look for customers reviews or testimonials and feedback.
Search for a local photographer, not the one who lives far far away and may find transportation issues on your wedding day. If that’s the case ask the photographer to be there very early on the wedding location or even one day in advance.
Meet in person with your shortlisted. Ask for years of experience, places he/she likes for shooting weddings, check any printed photobook or album, ask on how he/she got involved with the photography, do you feel a great passion or is mostly commercial or a side work?
Ask for a paid mini photoshoot before the wedding (must be paid or included on the package). This shoot will help the couple and the photographer work together and check if they click or not, you should feel some kind of connection or mutual liking. Try to follow his/her directions but also don’t be shy and suggest some of your ideas.
Wait for the result of the first shoot and if you are happy with the outcome you just found yourself your wedding photographer.