Thank you so much! I'm really glad you liked it!
For storyboarding I just used loose-leaf paper and had them laid out on my desk so I could see everything at once. For writing the dialogue, I used ellipsus, which is a google-doc alternative, and just copy pasted it into Dialogic.
As for writing the story, I came up with the initial concept, then the gimmick with the evidence, and then the body twists and worked everything backwards. I then figured out what I wanted the player to interact with the game, ie the box, the computer and the phone, and I made what I called an 'evidence-chain' where I determined what piece of evidence lead to what else.
When it comes to using Dialogic, I would recommend learning how to access features from the code, such as flipping variables and pausing for menus. The best example in this game is when you talk to someone the first time I have a variable that gets flipped, so if you call and talk to them a second time, an {if} statement gets triggered that sends a signal to one of the gd scripts turn on the end call button.
When it comes to timelines, personally I prefer to have a lot of little timelines. The phone, for example, jumps to another timeline when you input the correct string, using the string variable. That way if I need to edit something I don't run the risk of messing up too many things.
If you have a button or a trigger that opens up a dialogic TL, if you press it you can set it to open up even if the TL isn't null, in which it will automatically jump to that TL. I used this with the End Call button which just opens up a new TL that has a single line of dialogue then closes dialogic.
I hope that answers some of your questions!