What good ideas have you used or seen to get the party together at the beginning of a campaign? There's the tried and true having them meet each other as wagon guards, or in a tavern that's attacked. What have you used or seen to get the party together and get things moving in a fun, fast, and effective way?
At the time of this writing, my campaign has been running for over a year so I've seen some success with the method that I used to start things up. I had all of my party members come up with a reason that they wanted to go exploring to a certain new land in my campaign setting. Then, during the first session, the action started during a boat voyage (they were all on the same boat) and a crisis occurred requiring adventurers to leap into action to save the day. The party succeeded, so the authorities in charge of the voyage gave them some recognition in a ceremony and then went to that group when they needed help with additional tasks that required daring adventurers. My players were quite happy with this setup and mentioned to me that they preferred it over our standard "So you all notice that there are other adventurers in a tavern. Now go adventure." type opening. Since this was when 5e first came out, my party was quite pleased to jump straight into the action and start using the new rules.
To generalize this a little bit, you could get all of your players to come up with a reason to be at the place that the campaign will start, then during the first session introduce some crisis that they are the most qualified to solve, then have the people that witnessed their heroics treat them as a group and offer to pay them or provide services to them if they do some additional quests.
The crisis doesn't have to necessarily be combat. You could, for example, have everyone watching or participating in a circus and have a large fire break out. The party could attempt to save as many people as possible and assist with putting out some of the flames using skill challenges to determine success and failure while keeping things challenging, urgent, and exciting without ever having to make an attack roll.