I always like to take time in this panicked state of crunch right before uploading a build to look for the things to learn from this Jam:

Going in with a pre-team organized team can sometimes cause trouble with being creative with a new theme, with preconceived game ideas. 

You can always scale down from a high quality image, but not always the other way around (not always a good idea to start super big though!)

A large size / quality of basic tiles can make a difference - when you're using a lot of those tiles. (Make sure Programmers talk ahead of time with artist on size and object pixel density so that computers aren't burning up when rendering hundreds of high quality platforms)

I wonder if there wasn't a way to build levels that didn't absolutely have to wait until the tiles were done? Like, if they created a scene that allowed someone to apply 'cubes with collision' and then applied the textures after they were completed? (We were a little bottle necked waiting for someone to implement levels with tiles. Though the other coders were able to bug fix in the down time)

Artist again had a large push of assets at the beginning and then a drop off on the end of the jam. (Should pace them better, or have a good set of early need assets (textures/characters) and lesser need assets(backgrounds, UI, Title Screen/Win&Lose Screens)

One thing I missed this year was making sure all the coders sit next to each other. (Allowed for quicker communication between that team, which adds up over the course of the jam)

Everyone brought snacks - which was an amazing boon and increased efficiency and boosted morale!

When doing a food run for like, 15 people, make sure to get names and have a system!

If sleeping on site, make sure to bring plenty of blankets and a pillow! (and maybe some comfy pajamas)

I wish I had stronger smelling deodorant...