As an aging woman (on the higher end of 40something), I suggest reconsidering foundation altogether: do you really need it? Are you looking for full coverage to mask anything, or just sheer to medium coverage to even out your skin tone?
If you just need sheer/medium coverage, a skin tint may work best—especially a moisturizing one. You can also use a moisturizing primer under a skin tint. I’ve been happily using Lancôme’s Skin Feels Good tint. (They call it a foundation but it’s really more of a moisturizing tint.) This weekend I finally tried It Cosmetics’s Bye Bye Foundation, which is marketed as full coverage but can easily be applied sheer to medium. I also tried Bare Minerals’s Complexion Rescue tinted moisturizer and I’m on the fence about it. I need to give it a few more days of wear.
For under eye lines and bags: first, accept that primers and makeup won’t erase them. You can do a bit of optical illusion for eye bags with a concealer that’s one or two shades lighter than your skin tone, as long as you apply the concealer ONLY in the hollow of the bag—not on the bag itself or slathered all over your under eye area. Basically, you’re just trying to make that darkened hollow appear lighter, which can decrease the appearance of eye bags. It still won’t erase the bag, though.
I’d recommend a creamy or “radiant” concealer for under eyes with lines/wrinkles, especially if that skin is very dry like mine. I’m a longtime fan of NARS Radiant Creamy concealer. I hate Tarte Shape Tape: it’s too drying on me and settles deep into my lines. I recently tried Too Faced Born This Way concealer and it’s not bad... not as good as NARS in my opinion, but not terrible, and you get a lot more of it for the price. I’m not crazy about Lancôme’s concealers: they’re not super drying, but they don’t always perform as well as NARS.
Primers: you want a moisturizing one. My favorite of those is Lancôme’s Hydra Glow. Sometimes I wear just Hydra Glow, with no skin tint or foundation on top of it, because it gives me a dewy finish and kinda subtly blurs things. I do have Tatcha’s Silk Canvas, but I only use it on and around my nose because that’s where my big pores are, plus I find that primer helps tone down the oil on my nose. (I have combo skin: mostly dry except for my nose, which is very oily.) Don’t use a mattifying primer anywhere your skin’s not oily.
And if you do want a full coverage foundation, well... I don’t wear those often. Most foundations break me out or turn my face into a desert, and I don’t really need full coverage anyway. I can wear NARS Sheer Glow, Lancôme Teint Idole (cushion or bottle), and Too Faced Born This Way without much trouble, but I never build them up beyond medium coverage.
One more thing: try a good under eye serum and/or eye cream. There are plenty to choose from. Since Lancôme’s so generous with their free samples when I order directly from them, I’ve gotten to try several of their under eye products and now use one of their eye creams. I also use their Genefique Pearl eye serum. Some folks swear by Estée Lauder’s serum... I forget what it’s called. The Olay Reginerist eye cream works well for many people. There are other serums and creams that might work just as well for less money. But this plus keeping yourself hydrated (drink lots of water!) can go a long way before you even start to apply primer/foundation/concealer.