The beast races (Argonians and Khajiit) are different enough from human faces that I can't really offer any good suggestions beyond that whether or not a cat-person or lizard-person is 'beautiful' is highly subjective. Drawing out the nose is usually a good way to make them more animal-like. If you want a more animal-like character, exaggerate features. If you want a more human-looking character, eliminate exaggerated features.
Animal: For beast races, start by deciding whether you want something on the 'human' pole of the spectrum or the 'animal' pole. Orcs and Elves are best handled by minimizing the differences between their given features and human features.
