1 avocado, 2 eggs, salt, pepper, cheese (I used shredded cheddar and crumbled feta), assorted herbs (basil/chives/etc.). I wanted to add some kind of meat, so I used a cheese grater to shred some black pepper salami. I could see some cut up bacon being really good too.
Halve your avocado, remove the pit, and then use a spoon to widen the hole where the pit was. This leaves more room for your egg.
Try to get the yolk in first and then fill the rest of the space with the white. My avocado wasn't big enough to fit all of the egg white.
Some recipes said to add the cheese and toppings toward the end of the baking, but I added mine at the start and it worked out well.
I put the avocados in a small baking dish, but a tray will do just fine. Depending on the amount of egg you get in the avocado, your baking time may be a little more or a little less. You can poke it with a knife to make sure the egg is fully cooked.