If you want a salty taste, just like the ones you get in the supermarket add 1 teaspoon of salt per 500 mL water (but less is healthier).
When you make a lot of stocks buy biological herb plants. At the end that will be much cheaper.
If you don't use your stock immediately or fully don't add the salt yet. When heating it again, it will reduce a bit and the salt taste can be too much (but if it happens, you can simply add some water).
Beneath you can find a basic recipe, but vary with vegetables to get a different taste. You can also use broccoli or cauliflower.
Add noodles and some fresh herbs when done and you get a delicious soup.
Peel the carrot and slice it into three pieces.
Rinse the leek and slice it in half. Wash the celery sticks and break them into two pieces.
Quarter the onion and peel the garlic.
Fill the soup pan with 4 liters of cold water and add every ingredient.
Bring to a boil and let it simmer for 30 minutes.
Put a sieve above a big bowl and pour the stock into the sieve.