Why do teenagers do anything?
A few basic reasons:
- Their parents make them.
- They get to see their friends.
- They get something out of the experience.
You're heading straight for #4 and asking, how can we make the experience more meaningful to youth so they'll want to come? While it's an excellent question, I think it's the wrong one.
If you get kids used to the experience and make it part of their routine, this will make it easy for them to do it when they are adults and truly have the choice. How many Jews don't go to shul as adults because they "don't know how"? Or they're afraid of being judged for not knowing what to do? Or they just don't want to deal with a new experience?
So I start with #1: make them. In other words, it's not the kids you need to convince, it's the parents. I made my kid go to shul regularly in the year before her bat mitzvah. Now she rarely goes and it's totally her parents' fault. I made her go last week though and the tradeoff was she had to greet people before the service and attend the oneg (that part is easy) but she didn't have to sit in the service. Two of her friends came and they all hung out in another room. I wasn't thrilled with that, but at least they were in the building, right?
A lot of times teens would be perfectly happy to go to shul or anyplace else, but they won't admit it. So telling them they have to works like a charm. They can roll their eyes and scowl at you, but they actually want to do it. My daughter's like that every single morning when I drop her off at school. She says "do I have to go to school?" but only 30 seconds before we arrive (if she's actually sick, she'll tell me when she wakes up...and when she does skip school, she can't wait to get back).
Other times the teens might want to go someplace but only if their friends are there. Friend circles are really important at this age, far more than they are to adults or even to younger kids. Encouraging them to group message their friends so everyone knows who is and isn't coming is a plus.
But what can the shul do? I'd say give the teens special tasks. Some can be service related, like Monica talks about, and others can be separate (like helping to hand out the drinks for kiddish). Make sure friends are there.
Target kids by age. Teens do not want to go to "kids" events. My teen is only 13 but will not go to anything aimed at 11-12 year olds. So unless the teens are asked to help out (with actual important tasks, not just to be there), forget about getting them to kids programs.
And ask them. Every community is different. Maybe the shul wants to do a charity event. Let the teens choose and plan it, with some adult supervision.
Childcare is also important, because parents of teens also have younger children. Teens can help with the childcare too, which gets them in the building. Make it easy for the parents to come and the kids (of all ages) are more likely to follow.