My GameJam Philosophy
We're almost ready to get started and with so many new jammers I figure its worth sharing my philosophy when it comes to doing Gamejams.
As of 2017 Ive participated in (I think) ~5 game jams and Ive had varied levels of success. So Im by no means an expert on these things but I think theres some pretty solid approaches when it comes to a gamejam that can help a lot - all of which Ive learnt through my experiences doing gamejams like Ludum Dare.

My Approach/Philosophy:
1) Core Gameplay/Feature Focus
Focus on one single core feature for the game that will be fun. True for any game really, ie in Sonic the core feature of the game is him running really fast. The rest of the game is built around that (fun) mechanic. Or the portals in portal are another great example. It doesnt have to be complicated, but this is where you can focus on the fun/innovation categories of voting - not to mention putting together a solid game in general.
2) Game Foundations
Try to aim to get the foundations for the game done in the first 24 hours (and by that I mean main gameplay and controls, the win condition, lose condition, basic menu etc). Then the final 24 hours are polishing, adding more content, adding music and sfx etc. I dont think Ive every actually hit this goal, but its a good one to aim for as it means you focus more directly on that core feature and game states right from the start. You dont want to be implementing the lose and win conditions of the game in the final hour while half asleep and trying to build your final submission, trust me.
*3) Identify Weaknesses *
Be aware of your weaknesses/timesinks and be prepared to compromise. Easier said than done I know, but if you know something will slow you down try to be as aware of it as possible. If you notice during the jam youre spending too much time on a feature or area of work, compromise on it and wrap it up - get onto the next big of work asap. If you dont know what slows you down, reflect after the gamejam on areas you got stuck with.
4) Promotion & Accessibility
Ive struggled with this in the past, using the game engines Ive used in the past plugins were needed to run in-browser, or a download of the game has to be put up - which isnt the most accessible or motivating. I know Id rather just hit a link and get right into it. It doesnt clog up my PC with downloads either I dont have to unzip/manage/find files etc. Its lazy but its how things are when you want to play 100 games after a game jam. Im always extra keen to play a game if its one click away.
Promotion is a no brainer too, but super important. Through the gamejam I try to do a few posts and show off some nice gifs or video, it gets the game out there and people interested even before the jam is over. I also try to make a nice looking splash screen, because that will draw people in to test and play your game, which is crucial in the voting round. Making a game trailer after/during the jam is also a good way to show off the game along with doing post-mortums and posting timelapses of the whole thing.
5)Sleep!
...At least in the first 24 hours anyway. I always aim to get decent sleep in the first 24 hours, and then (if possible) pull an all nighter for the last 24 hours and push some serious game dev hours. Youve always got the next day to have a good sleep and recover, so optimise that time spent developing your game. I know theres a lot of different suggestions when it comes to this, but this is whats worked for me in the past.
The biggest successes in when it comes to gamejams is learning more about your strengths and weaknesses when it comes to game development and everything related to that. Its always a good exercise in self reflection.
I hope my tips help someone!
Goodluck to everyone for LD40!