Preheat your oven to 350 F.
First, find a large rectangular pan and fill it with about an inch of water. This is the classic "water bath" method that is used in cheesecake recipes to enable an even baking throughout the custard.
Next, place some smallish Pyrex dishes (or other ramekin-type dishes) in the water bath. No need for them all to be the same size. You can see here that I used three small ones, a medium one, and three clean baby food jars. Why the baby food jars, you ask? I'm experimenting with them as a way to send custard with my three-year-old to preschool in the fall, when I'll be packing her lunch three days each week. (They turned out perfectly baked in these jars, by the way! I poured the excess off the full ones into the big Pyrex dish so that there would be about 1/2 inch to expand during the baking.)
OK. So you have your water bath pan, filled with your little custard dishes. Get yourself a nice, easy, primal custard recipe. You can experiment with it after you're used to the process. I like the Son of Grok banana "Caveman Custard" recipe. In my head, I call it "1-2-3 custard" because it requires one can of coconut milk, two bananas, and three eggs (along with a dash of cinnamon). Whip up your custard batter, and pour it into your ramekins. (I did nearly-full baby food jars, and about 1/2 inch deep in the larger dishes.)
Stick it in the oven and bake for 45 minutes at 350. Take them out of the oven, but don't remove them from the water bath. The more gradual the cooling process, the prettier your custards - that is, the less likely they are to crack on top. Once the water bath is completely cool, put the custards in the fridge to cool and set some more overnight.
Oh, and remember the part about experimenting? Now that you've done your basic custard recipe, shake things up.
Add a drizzle of walnut oil to the custard batter for some added fat, and a deliciously nutty taste. (Just don't do it all the time, though, since walnut oil is omega-6 heavy. Maybe make the custard with Omega-3 eggs to offset?)
Mmmmm, walnut oil in a pretty tin.
While you're experimenting, add nutmeg, ginger, vanilla, etc. to your liking as well.
Oh, and let's talk toppings. In the morning, I top my chilled custards.
See my humble banana custard? (And yes, even with gradual cooling, there's a little crack. So sue me. This is another good reason to talk toppings - because they hide cracks!)