I've on of those glass carafe's with the insert for coffee grounds, but I use my french press because it's just easier. I do 1:4 course ground coffee to water, so it's a concentrate. I use 200g coffee + 800ml water in my press. I let it brew in the fridge for at least 12 hours, up to 18. Can go to 24, but that's not my preference.

At serving time, I like it with generous 1/3 coffee concentrate + lean 2/3 water.

If I did not want to make a concentrate, but to drink straight up, then I'd go 1:8 or 1:10.

It's all about taste though! You'll find your sweet spot after a couple brews. Course ground coffee makes a much "cleaner" cold brew than regular grind. I don't generally filter mine unless its super cloudy.

You’re certainly on the right track. I only cold brew occasionally, but almost always use 1:6 coffee to water and dilute 1:2 afterward with either ice or hot water, depending on my preference. It’s also what I use when expecting overnight houseguests. Start with 1:8 or 1:6 and experiment thereupon if you feel up for it.

For an indulgent treat, add sweetened condensed milk!

Adding or subtracting a paper filter can be interesting.

Airtightness is worth thinking about to keep the brew tasting fresh, especially for concentrate storage.

Upgrade your ice using filtered water, maybe big cubes vs ice tray.

And of course, try a hot brewed ice coffee with the same beans to compare.

You may have to experiment a bit with your first couple if batches, as the end results can vary depending on the quality/type of filters, and the strength of your preferred coffee. Add or subtract coffee from your batches until you get your desired strength.