For immersion brewing, I usually up dose by about 15% compared to drip brewing.
That means that effectively a 1:15 ratio becomes a 1:13 ratio on immersion, and a 1:16 ratio on filter becomes a 1:14 ratio on immersion.The recipes below use slightly different ratios, the idea being that you can start at 1:10 and go to 1:15, with one example right in the middle.
Without going into much detail, it has to do with concentration gradients and how the coffee solution gets stronger or weaker for the given brew method.
This video goes into more detail:
For aeropress I would brew the following:
12.5:1 ratio, I think aero press holds about 225 grams of water, so 18 grams of coffee to 225 grams of water. Finer than kosher sea salt grind size and probably about 1:30-2:30 of time, then press.
If you want it to be stronger, give 10:1 a try and dose 22.5grams to 225g water, and maybe a slightly finer grind size to compensate for the increase in dose.
If weaker, try 15:1 and dose 15grams to 225 water, grind size maybe slightly coarser
For a French Press or Press Pot, scale the recipe above to however much coffee you may want, and adjust the brew time to 4:00-6:00 for larger batch sizes.