Directly in my own blend of seed raising mix (soil), in black plastic pots, 4 inches across and 5 inches deep.
Never plant in clear plastic containers, roots need absolute darkness to develop properly.
Always plant more seeds than you need, not all seeds sprout, and not all seedlings are perfect,- there will be duds. With extras you will be able to choose only the healthiest and best seedlings to continue with.
Most seeds these days, bought from reputable sources and from quality breeders have better than 95% germination rates, I usually only get 2 or 3 seeds out of sixtyish each outdoor season that never sprout at all. Yes, I am very choosey when it comes to my girls! I keep about 30, give away about a dozen and the rest I just don't like for whatever reason and those never make it past a week.
You can't grow nice plants from crappy seedlings!
From extensive test that I have done, there is absolutly no need to drown seeds in a glass of water or pre-sprout them in paper towel, as this just delays development by anywhere from 3-10 days and increases the risk of damage to the embryonic seedling.
They definitely grow the fastest and healthiest when planted directly in the substrate, just like in nature.
Just keep them moist, not wet and never let them dry out and all should be FAB Virgil!
Otherwise, if you are unsure about starting in soil, 2 inch/50mm rockwool cubes work a treat......
Surprise, surprise, if you go to the germination week in my diary "cannabis conundrums", I have posted an informative and easy to follow tutorial about starting seeds in rockwool cubes that is almost foolproof, if you are keen for an insight into this method.
In week 7 of the same diary you will find pictures of a 3 week old seedlings' root system, which will demonstrate why deep pots are essential for healthy seedling development and shows why stupid tiny coffee cups are so inadequate for seedlings.
For further tips, try the Mandala Seeds website and click on theiir "grow guides" where they have a fairly comprehensive run down on all things related to growing(!), including recommendations for fertilizers and soil brands, which can be very helpful and quite enlightening and far more in-depth than what I am prepared to write here!
Hope this helps, Organoman.