Is a trial necessary? Yes! You absolutely need a trial no doubt about it. I mean I've definitely done wedding glam without trial and they still look gorgeous, but I would never advise against it.
Your wedding is one of the most important days of your life, having a panic attack about something minor as mascara is nothing I haven't seen before (it was me a week ago) and so freaking embarrassing. You want to make sure you know your artist well and trust them with your eyes closed and no mirror in sight.
It is normal to feel anxious on your wedding day, your artist must be able to give you the calming energy you need before you walk down the isle. You will want to get to know each other to see if the vibe is right and if the artist can demonstrate what you are looking for, the last thing you want is to hire someone for your wedding day who you don't actually like and is impatient with you when you're a nervous maniac. Not only will it make you feel uncomfortable but it can be awkward, you definitely do not want to be around a vibe killer on the morning of your wedding.
A trial gives you the opportunity to sit down and talk to your artist about what you'd like and what you feel comfortable wearing. If you have never had your makeup done before, have a trial maybe even two. Your wedding day is not the day to try something new, It’s a day where you want to be fully confident that you'll look exactly how you've always envisioned. Last minute changes happen but if you’re not used to an occasional beat face glammy moment then please! Im begging you! have a trial so you know what to expect.
You also want to give the artist a chance to see what your skin situation looks like. It gives us the opportunity to try out different products on you and see how they sit on your skin and last during the evening. I also love to give my brides a detailed regimen to follow leading up to their wedding, because yea - you may think you have perfect skin but an artist will tell you whats really up. I love my brides and try to educate them on how they can achieve model skin on their own for the wedding.
If you DO decide to book a trial with your favorite artist please arrive with realistic expectations. Do not show a photoshopped image of Kim K with 12 different filters. Please remember that its your wedding day and you're meant to look like yourself.