Ich schminke mich lieber als er sich.
is this incorrect or correct?
not really.
Ich schminke mich lieber als ...
means
I would rather put make-up on myself than ...
the "als er sich" sounds very clumsy and awkward and I cannot tell what you are trying to say.
Can you state the English sentence that you are trying to translate?
there is none. im trying to determine if that sentence is grammatically correct or incorrect.
This IS grammatically correct, but it sounds weird (no offense :P).
It means "I would rather put on make-up than he would", more or less. There would be better-sounding ways to say this although it is correct.
The sentence "Ich schminke mich lieber als er sich" is grammatically incorrect in German. The correct sentence would be "Ich schminke mich lieber als er."
To explain the correction: In German, the comparative form "lieber als" (meaning "rather than" or "preferably than") is commonly used to compare actions or preferences. In this case, "Ich schminke mich" means "I do my makeup" or "I apply makeup to myself," and "er schminkt sich" means "he does his makeup" or "he applies makeup to himself."
So, the corrected sentence "Ich schminke mich lieber als er" translates to "I prefer to do my makeup rather than him doing his makeup."