Franklin, what I do is not complicated, it just appears so because I use so many things that most people don't have lying around. Since I mainly grow tropical plants and keep all the media components necessary to grow them, I just use what I have. I am a big believer in milled sphagnum moss and Black Kow as the backbone of my potting mixes and then anything added to open it up, making it well-draining, will produce good results.
Deb, I just noticed that the Burpee Seed Starting mix has some sort of fertilizer in it. Tell me what that fertilizer is before you start adding additional fertilizer to your seedlings.