Try all kinds to see what works for you. Make sure they are clean and have good drainage. If you are using a fiber or peat pot, soak it well before adding soil. Dry fiber pots draw moisture away from the soil. If you have saved seeds that you purchased last year, test the germination rate before planting.
Nothing beats a good commercial medium because it is sterile and free of unwanted weed seeds.
It's a good idea to water the soil and allow it to drain thoroughly before sowing the seeds. Make a hole for each seed with your finger or a pencil. Keep in mind that most seeds need to be planted four times as deep as the seed is wide. If your seeds are very fine, cover them with a fine layer of soil. Moisture and Humidity Germinating medium should be kept evenly moist but not soaking wet.