In the US eastern white pine and Douglas fir are safe. However, safe isn't the only consideration. What is the active ingredient? Is it in all pines or just some? Maybe there is more than one compound that is helpful. I've been looking and found information is pretty spotty. You can go to an asian food market (or online) and they probably have the classic Korean red pine tea. To answer the preparation question, the dried needles are really tough. Mine came with instruction to soak at least half an hour and boil up to 2 hours and then let steep. The powder is much easier. Soak a level teaspoon in a cup of water, boil in microwave in cup, let cool. Even better, soak the powder in enough rum or vodka to cover for half an hour, then boil etc with a spoonful of sugar. This extracts more piney-ness. The alcohol boils off.
EDIT: To clarify, only a little alcohol is used to start extracting essential oil. Don't use a cup! Then fill the cup wth water.
Article covering much more: https://www.oom2.com/t75509-is-pine-needle-tea-the-answer-to-vaccine-shedding-transmission#:~:text=1%20Use%20roughly%2075%25%20alcohol%20%28such%20as%20vodka%29,duration%20of%2025%20minutes%20for%20the%20ultrasonic%20extraction
If you are using fresh needles, demo: https://www.bing.com/videos/search?q=emmymadein+japan+pine+needle&docid=608002704478508970&mid=372C0927220FD373B8EA372C0927220FD373B8EA&view=detail&FORM=VIRE
In the US eastern white pine and Douglas fir are safe. However, safe isn't the only consideration. What is the active ingredient? Is it in all pines or just some? Maybe there is more than one compound that is helpful. I've been looking and found information is pretty spotty. You can go to an asian food market (or online) and they probably have the classic Korean red pine tea. To answer the preparation question, the dried needles are really tough. Mine came with instruction to soak at least half an hour and boil up to 2 hours and then let steep. The powder is much easier. Soak a level teaspoon in a cup of water, boil in microwave in cup, let cool. Even better, soak the powder in enough rum or vodka to cover for half an hour, then boil etc with a spoonful of sugar. This extracts more piney-ness. The alcohol boils off.
Article covering much more: https://www.oom2.com/t75509-is-pine-needle-tea-the-answer-to-vaccine-shedding-transmission#:~:text=1%20Use%20roughly%2075%25%20alcohol%20%28such%20as%20vodka%29,duration%20of%2025%20minutes%20for%20the%20ultrasonic%20extraction
If you are using fresh needles, demo: https://www.bing.com/videos/search?q=emmymadein+japan+pine+needle&docid=608002704478508970&mid=372C0927220FD373B8EA372C0927220FD373B8EA&view=detail&FORM=VIRE