How do you bake both round and flat faces with details while you have to subdivide the low poly mesh? Bcs when you do, round shapes turn into flat faces and you get this faceted look.
Can I see an example of what object you're baking? If it's something simple where skewing won't be an issue, subdivision wouldn't be necessary. If it is, you could try using creases to tighten up only the sharp edges.
It is the gun from the tutorial - the "body" part with floating details and round part in the bottom. You have to use subdiv bcs of the details being under an angle. With the crease, do you still subdiv the mesh?