With my limited gardening experience, I'd never grown tomato from seed and have always been told it was difficult to do and I'd be better off purchasing the plants from one of various local sources. Since I had plenty of time by starting things indoors, I figured I'd buy a pack of seed and try them, and if they didn't work out, I'd still have more than enough time to purchase plants by the time the weather indicated it was time they go outside. Obviously starting from seed would be more frugal, as the cost for one pack of seed is about half the cost of a single plant.
I did some reading and found several tricks to starting tomato seed successfully, and I have living proof that they work! First, I found that tomatoes love eggshells, as they provide a significant amount of calcium. There are several ways to introduce tomatoes to that source, but I opted to start them off right away by planting the seed in the eggshell itself. I believe I had 100% germination (or very close to it) and as they sprouted, I lovingly called them egg babies, or eggplants!
Once they develop the second 'true' leaves and are ready to 'pot up', you can just tap the shell on the bottom to loosen it, then plant the entire eggshell with the seedling within. That way you are not disturbing delicate little roots, and the seedling will still get the benefit of calcium from the shell as it leaches into the surrounding soil.
I started my seeds at various times so I will (hopefully!) have tomatoes coming in throughout the summer. Here is a shot of one 'egg baby' with it's big brother that is already in his forever home.
Whether already in eggshells or not, you can still give the seedlings a calcium boost by adding more eggshell to the soil at any time. Well before the weather permitted putting them outside full time, I worked the soil by adding used coffee grounds and eggshells whenever I had them. Worms love coffee grounds, who are of course good for any garden, as they assist in providing proper aeration for a healthy root system.
For on the spot nourishment, after digging your hole in the larger pot or the ground, simply drop a few eggshells into the hole before placing your seedling and refilling with soil. Here's a shot of my family of tomatoes in various stages of development. I believe the two in the above photo are the two in the larger blue buckets here.