Ortal doesn’t sweat doing the skin first - however, she holds the finishing touches until the very end to see what accents are missing in the whole look. However, if you worry that you will end up with a panda for a model - do skin after the eyes. Just forget the rules and do what feels comfortable with you.
Now, for the skin - main rule here is to apply the foundation in thin layers. Think painting and imagine yourself as Michelangelo - Ortal recommends working with flat painter brushes that push product better into the skin, so that it doesn’t look cakey or overloaded in the end.
Going through products, pick one heavier coverage foundation or use a few and layer them separately. However, try them out first - the products should be easy to blend and have the same thickness as not to separate so easy. Same rules apply to concealer - layers and blendability. Just don’t forget to check the ingredients, e.g. water based products don’t mix with oil, unless you want to end up like a mad chemist with an explosion that is probably going to be a hysteric bride.