The most obvious way to avoid a criminal record is to not commit any criminal offences. Sometimes, we are simply not aware that our actions carry criminal consequences. If you are unsure whether your conduct constitutes a criminal offence, consult a lawyer. We are ethically and morally obliged to inform you whether your conduct or planned actions is against the law.
Of course, if you are reading this, you may already be facing criminal charges. That does not mean you will be convicted or that a conviction will result in a criminal record. Even if you are guilty of the criminal offence, there are sentences that do not involve a criminal record and there are extra-judicial measures that may also be appropriate in your case.