In finite verb forms (like present indicative pettino) clitic pronouns always come before the verb: mi pettino. You only attach them in non-finite forms:
• Infinitive: voglio pettinarmi
• Gerund: pettinandomi
• Imperative: pettinati (tu)
They’re similar but not identical:
• Pettinare uses a comb (pettine).
• Spazzolare uses a brush (spazzola).
Both mean “to tidy/arrange one’s hair,” but the tool differs.
Use the passato prossimo with the reflexive structure:
• (masculine speaker) Mi sono pettinato i capelli stamattina.
• (feminine speaker) Mi sono pettinata i capelli stamattina.