Skip foundation and instead use a tinted moisturizer, preferably one with sunscreen like this one from Sephora that's SPF 20. Dust a little translucent powder over it for a modern touch or if you're feeling a little too greasy.
Eyes are amazingly simple, especially with these eyeshadow palettes. The one from Urban Decay comes with a shimmery eye primer and has shades in gorgeous browns, greens, and blues. Another plus is that it's vegan! Malibu Barbie made her debut in 1971 and Stila put together this collection in her honor. It features pale lip gloss and sheer eyeshadows, plus mascara for a modern take on the Seventies look. Mascara actually declined in popularity back then, so use a clear version to subtly define your eyes if you'd rather be authentic.
Add blush and bronzer on your cheeks for a sun-kissed glow, like you just got back from an afternoon of tanning (please, please don't actually go tanning). NARS has the perfect duo of both in a convenient compact featuring Orgasm blush and Laguna bronzer. Finish with some clear lip balm like Rosebud Salve and you're set!
Side note: also pictured is Glamour magazine's July 1971 cover featuring a then-unknown Cybill Shepherd, my mom's personal 70s makeup inspiration :)