The mix in which you sow your seeds should be loose and free-draining with a high organic material content. Those of you in the UK can use John Innes seed compost. In the US, a good quality bagged compost especially for seeds will do. You may need to add extra grit, perlite or bark fines if it doesn't look like it will drain well. Pots You can use clay or plastic pots.
Smaller pots tend to dry out faster.
It's sold in most locals as poultry starter size grit, available at feed and grain stores. Just make sure it's pure grit, with no added salts or calcium. Fill your pots and level them off. Sharply tap the pot on a firm surface to settle it. Space your seeds an inch apart.