I used 100 grams of Ancient Sunrise henna and a mildly acidic mix.

I mixed this up and let it set for 18 hours and applied the next morning. I left it on for a total of 6 hours.

My beginning color was dark blonde with some highlights.

I absolutely love it!

Notes and References
Henna: https://www.mehandi.com/Mehandi-com-Ancient-Sunrise-Henna-for-Hair-s/121.htm
Don’t have fruit juice on hand? Keep some fruit acid powders in your cupboard.
Mildly acidic liquid: https://www.mehandi.com/Fruit-Acid-for-henna-dye-release-s/299.htm
More info on mildly acidic mixes: https://www.tapdancinglizard.com/henna-and-acidic-mixes/
Henna color oxidizing ("rusting"): https://www.tapdancinglizard.com/mixing-and-testing-your-henna-mix/ pp.25-29

Video How-To
Going red with henna: https://vimeo.com/manage/videos/739464950