If you want to make your own gelatin, the easiest way is to make a clear gelatinous broth. Toss a pig's foot in the slow cooker and add some water and salt. Let it go overnight. Strain and refrigerate the broth, then remove the layer of fat. It'll be thick like jello, and I mean really like jello. You could make a nice aspic this way or just heat it up and it turns into broth again.
I'm testing having some of this gelatin broth every day this week and see if it makes any kind of difference.
Female, 5'3", 50, Max squat: 202.5lbs. Max deadlift: 225 x 3.