I'm not sure what lighting you have but I would try sunny windowsills and/or extra lighting. The plants you choose all like sun so for indoors growing I would give them all the light you can.

With the mint, I would cut back on the water. Too much water can damage plants - yellow leaves is one of the hallmarks of too much water. I find it much easier to kill a plant with too much water than to kill a plant with too little. If ever in doubt, err on the side of too little water. Droopy leaves or other visible signs of stress will tell you if you are too dry. Learn from that and adjust your watering to be a little more often. With indoor plants about once a week watering should be good unless you have very dry, hot conditions.

As an aside, I see herb plants sometimes in the produce section of my local market. On a whim I have bought a plant or two...or maybe more!....this way. They have *never* faired well. All died in short order - I've been a plant person long enough to know it was not my care or lack there of. Some plants have had bad treatment/care and it is hard for the average person to overcome that once they bring the plant home. I'm not sure where you got your mint but it is possible that it was reacting to conditions and care it received before you bought it. Mints are tough so with a little care and love you should be able to nurse it back to health.

FataMorgana

Extra water, yellow leaves, leaves dropping off. Its too wet.. Reduce the water, also repot it so it will have good drainage. When new seedlings wither near the soil, its damping off and will 'strangle' the plant stem and they soon die. Usinga high quality seed starting mix that is sterile will reduce the issue of damping off. The biggest cause of a quickly dieing plants is too much watering.

Well, I'm watering the mint less, and I removed the dry/yellow parts, and it looks pretty good - reaching for the light, and probably wishing it could get outside and take over the whole yard!

The cilantro is still doing okay, though the stems aren't as strong as the plants I had last year. The basil just barely sprouted, with two tiny leaves on the end, and it looks kind of depressed and limp. Any ideas on that? I planted the seeds in the same pot I used for my last basil plant (which may have died because it wasn't getting enough light), and in the same soil.

Sunlight and herbs are very necessary. Using pots and soil over again tend to reduce the plants health. Cilantro can be grown in shade and cooler temps, but basil and mint need plenty of sunlight. Even my small seedlings right now are under 18 hours of plant lights only 2 inches away from them. Once they get a little bigger they get put outside in my small greenhouse to harden off. Then get planted in the edges of the garden. I never reuse a potting soil again

I have quite a bit of basil (and rosemary, chives, fernleaf dill, oregano, mint, parsley...) that I keep indoors. I've had a lot of sucess with my semi-indoor herbs. I blame it all on the wonderfully educated plant lovers here!

After I lost all my plants moving, and to my chronic plant newbie over-watering (fungus gnats are not your friends), I got some books, and did some research, and I started over indoors from seeds in individual pots filled with Al's soil mixes...depending on the plant. I plan on keeping them in their pots all summer on my deck, and some of them, like the rosemary, I'll overwinter in my kitchen. Mmmm I have plans for that little plant.

The people above are right, basil needs lots of sun and warmth. Mine are on a shelf just a few inches away from my big south windows n a very very sunny room with BIG windows on all sides, and I was still giving them a few hours a day from a plant lamp during the dark last few weeks of winter.

I think the only reason my plants are doing so well this year is because I found this forum. With Al's soil mix and everyone else's wonderful advice, I have very very happy herbs, and a very very happy chef in my kitchen

So my only advice is this:
Listen up; these gardeners know their stuff.
:D

If you get the gnats again (and yes, they do fly from plant to plant!), use yellow stcky traps placed horizontally on the edges of the pots. I also use a Bt mix and soak the roots a few times to kill and drown the maggots. The traps catch the fliers, and the Bt gets the grubs/maggots. These usually come from soil that was dug from outsoors and used as a potting medium indoors. Gone unchecked, within a few weeks, the fungus gnats infest every plant in a house, and their maggots destroy the roots of houseplants. Using sterilized potting soil is necessary to prevent these bugs from damaging plants

Yeah, I haven't seen hide nor hair of the little jerks since I got rid of them the last time. Am much more carefully about my soil and watering. (:

The mint is doing very well, but it has little bugglies on it. Aphids? I don't know. They may be what's leaving little trails on the leaves. Whenever I find one, I squash it, but there must be a better way to get rid of them.

The cilantro is sending up new leaves, but the stems are weak, so the main stems are horizontal while the offshoots of said stems are vertical.

The basil seedling bit the dust. Now that I know how much light it needs, I may be successful in planting it again. Any other ideas for growing herbs indoors? I mean, any particular recommendations for herbs I might try growing?

My basil has always been fine, and not a single loss even after nearly a month in seed starting soil. Cilantro likes to have its seeds planted about half an inch deep. Mint with bugs- The safest insecticide is neem. Suggest spraying every 10 days, for 3 sessions. Be sure to apply it to the underside of the leaves. If these plants are outside, and infested with bugs, you can cover the plants with a light weight plastic fabric. The fabric blocks most insects, while still allowing air and sunlight through.