Log into your Steam account only via Steam or platforms you are confident about.
Always check a website link you are about to click. Pay attention to the connection type (it should be HTTPS rather than HTTP) and URL. Remember that scam sites often use slightly misspelled URLs of legit platforms.
Change your Steam passwords regularly. You can change your Steam login credentials by clicking “Forgot Password” when logging in to Steam or selecting “Change Password” in your Steam client setting/preferences. The first option is preferable since it allows you to continue trading on Steam without a trade suspension period.