I just finished up Fishfest too! My first ever jam was a 72 hour jam. My first team was pretty small (like less that 6 people) and we ended up making an awesome game. 

My advice for you would be to make sure you keep everything organized, keep your idea sweet and simple, and have some sort of checklist for everyone in your team. A big thing I've noticed when doing these jams is that sometimes teams lack proper communication with each other- mainly due to being in different time zones. Whether you are the leader in your team or not, make suggestions to whoever is about adding specific channels to a Discord server (if you're using that for communication) and/or use websites like Trello to track the progress of your game. Make sure to post updates on your work and be honest about meeting deadlines.

These are just a few of many tips out there. Also, make sure to get plenty of rest and food; you can't work well if you don't get your sleep or have food in your stomach! If you have other questions or concerns, feel free to ask! Have fun ^_^

Also, get your idea done quickly. (mostly quickly, don't rush or sweat it) For me, I've been unable to submit to several jams because I took so long to handcraft the perfect idea that I couldn't finish the game    :(   Remember that you can ruin a great idea with a bad game, but you can use a great game to help an underdeveloped idea.