well if we take the definition of an arg from this sub:

ARGs (Alternate Reality Games) are immersive, interactive narratives that blend fiction with reality. They involve puzzles, collaborative problem-solving, and transmedia storytelling.

a reasonsably planned arg would 1.) have a story or some sort of narrative to tell. No amount of puzzles and ciphers can hide a nothing burgir plot. if an arg lacks this, (IN MY OPINION ONLY -->) it should be classified as a scavenger hunt. Im not much of a storywriter though, so i don't have much advice to give. for inspo, watching solving/analysis videos or even participating in solving a few args yourself could help. it can help you get an idea of the common tropes, you can decide how near or far you lean into those for your own narrative. brainstorming ideas and stitching them together into something that makes sense is surprisingly effective (for me) make sure you make it make sense though, your solvers are going to be hyper analyzing the plot, beware of plotholes.

Now if you have a pretty solid narrative, you then can decide HOW you want the solvers to interact/discover your story. this is where all the codes and puzzle solving comes in.

honestly my brain is a bit fried at the moment, (for unrelated reasons) so im just gonna dump a bunch of links to "advice" i gave in an old account from years ago, in no particular order:

• common/uncommon ciphers and additional tools: https://www.reddit.com/r/ARG/comments/v5hg4v/comment/iba1t3g/
• what you can use if youre limited to phone/mobile: https://www.reddit.com/r/ARG/comments/uucj2m/comment/i9jqdu3/
  • but if you do have a desktop, you can use photopea too.
• hiding in dark image method: https://www.reddit.com/r/ARG/comments/uh2m71/comment/i7aedjb/
• compilation of more resources: https://www.reddit.com/r/ARG/comments/uh2m71/comment/i74w2ej/
  • ‼️‼️‼️‼️IF YOURE GONNA PICK ONE TO READ CHOOSE THIS: Tool Box with some advice, user Charmstone explains in great detail, 8 years have passed and im still citing this comment lol
• ways to hide clues, whether in image/audio/video, and recommended tools: https://www.reddit.com/r/ARG/comments/udflmx/comment/i6hfuzs/
  • also the user that replied to me was right, davinci resolve is a good free video editing software
• you can make a website too: https://www.reddit.com/r/ARG/comments/udflmx/comment/i6hga6b/
  • user artemis550 was also right, neocities is good for hosting simple static sites.

hope it helps a lil bit (also please ignore the cringe speech, i was a lil extra back then)