The eggplants we have appear to be extremely efficient in their pollination as every flower that blooms, bears fruits, and So far, in the past year or so, I am yet to see flowers that didn't turn into fruit.
From this experience, I can say that the eggplant is an easy going vegetable plant that can give good results even in small pots or grow bags. Just that it needs heavy nutritious feeding around the time it blooms and bears fruits, which mostly happened, for the plants I have twice a year, the first time starting September - November, and the second time around March - April. None of the old plants died, new did came up from the seeds that were harvested and later sown in more posts and bags.
The plants took around 3 months become mature enough to start blooming and bearing fruits from the very delicate seedling phase I received them in around July, last year. In all, the egg plant is a hardy no-fuss vegetable that's easy to grow. What you make from the fruits you get is up to you. From what I know, eggplants are not so versatile to be added in every dish, but then there are a lot of finger licking recipes that do use eggplants, a lot.
It takes a flower around 7 to 10 days to become a harvest ready fruit, beyond which, seeds will start developing and it'll become harder. A good test of the eggplant fruits to check if they're good enough to be harvested is to grab them in your hands and try pressing them a little. While they are firm and still soft to press, it's ready to be harvested. Since these come in a lot of sizes, and shapes, small egg like size and shape, longer ones like elongated balloons, bigger ones are also there. While you can find eggplants in three-four different colours, white, violet/purple, green and a combination of green-gray, most often you'll find the bigger ones to be in purple/violet colours, green/gray ones a bit smaller, longer ones available in green, violet and white colours, and the smallest ones in violet and white.
The eggplant bears the smaller fruits usually in bunches of 2 to 4, since the flowers bloom too close to each other. The bigger ones usually grow farther.
The plants need to be fed a high amounts of nutrients, around the time of flowering and fruiting. The more the merrier. Since the plant blooms continuously in tranches, you should keep in mind that it needs to be fed regularly, or the fruits will start reducing in size. For a well fed plant, the first fruits define the kind of produce you should be expecting. Any decline in the numbers or size should be an indicator of low nutrients in the planting medium.
I am not very fond of these as a potential vegetable which would feature as a favourite in my personal must haves food list. So, while I try to avoid it, you can't really say no to something you've grown and harvested yourself.
And finally, you see here the yellow eggplant fruit. Yellowing is nothing, but just ripening of a fully matured fruit. As it grows beyond the harvesting age, and since you did not harvest it, the fruit starts hardening quite and yellowing also starts, and goes on until the fruit completely turns yellow. At this stage, you should let the fruit stay om the plant for a good enough time. A month or anything longer is just fine. If you want to save seeds, you can simply take the fully ripened fruit from the plant, put in a long vertical incision in the fruit, and let it out in the sun for a couple of days, for the fruit to dry up, and give away the seeds itself.