Consummate the marriage
This is the easiest step because it involves having a sexual relationship with your partner. That step either you have it or you don't.
Present yourself and your partner as husband and wife
This can be proved by other people that will indicate to the court that you have in fact told them that you and your spouse were married, or were husband and wife.
Enter into a contractual relation together as husband and wife
If you place your lease at your apartment or have any contract with your partner entered as husband and wife this would be indicative that you are married to your partner.