Oh, dear. Last year I did have an odd one. A beautiful, several years old rosemary that I was very attached to up and died for no reason I could think of, and my basil all keeled over and died before its time as well. The only thing I could think of is that both plants must have hated the cocoa mulch I topped the bed with, although the myriad of other herbs did ok.
Mint needs wet feet. Plant it near the roof's downspout or a faucet (especially one that leaks!). Most herbs don't like a particularly rich soil. I've found though that gardening can be pretty capricious. I once couldn't get cilantro to grow in my herb garden to save my life, only to have an almost eternal plant pop up in the middle of the lawn. Hubby mowed it down weekly, but I had fresh cilantro for a couple of years from that silly plant!
I've found that starting with seedlings from the store rather than seeds is best for me, for most plants. I start from seed with basil sometimes (now in a planter rather than in the ground where it died last year), and dill "volunteers" every year. I also have a few perennials that come back every spring. You might look up plants that "like each other". Basil likes to grow near tomatoes, and I've also found it likes growing in the barrels I grow peppers in. Marigolds are said to repel some insects, and nasturtiums are disliked by moles and some other burrowing diners of your garden. Both have flowers that are lovely and tasty in your salads.