I'm sure there's lots of curious bides out there on this topic, so I thought I'd share my experience and maybe answer some questions for those wanting to try it, but maybe unsure.
I wanted to give lash extensions a go for the wedding, and then have them for our honeymoon afterwards (less makeup application time). It was recommended to me by the lash technician to get the extensions a month before the wedding, and then do a fill right before. I would say the application process is pretty long (2 hours), and that it doesn't hurt, but it can be a bit uncomfortable.
Getting used to the extensions took me a few days. In the shower, the water makes them super heavy, and the way you wash your face, or apply your makeup requires some adjustments.
The first thing you need to know that I'm a fair skinned redhead, and I have naturally blonde lashes. And the other thing you need to know is that lash extensions fall out way faster than you think they will! They looked great for about 7 days, and then my natural lashes began to grow in, and because you can't wear mascara, the more they fell out, and the more blonde lashes grew in, the less dramatic my lashes looked, which kinda defeats the point of them. I decided to cancel the fill appointment and get them removed instead. By the time the appointment came, I barely had any extensions left (and I BABIED them!).
I feel like this is a product that greatly benefits those with naturally dark lashes who can keep the extension look going for much longer. Based on my experience, I would actually suggest trying the extensions earlier than a month before the wedding. This way, if you decide you don't like them, it gives your natural lashes time to fill back in. Lash technicians will say that they don't harm your natural lashes, but I definitely noticed that my lashes were much shorter, and sparse after the extensions came off.
This was just my experience with them. I know lots of people love having them, and that's great. I wanted to love them too, but I didn't feel like this was worth my time and money to keep up. $100/application is a LOT of money to pay every 2 weeks, which is the rate I'd need to get them filled at for them to stay looking good. It was fun to try, but I know now that this isn't the route for me.