Phone bills, maximums receipt regarding wedding expenses, after and before wedding expense you and your partner spent even a restaurant bills. I submitted around 200 bills, this will help to stong the case and photographs maximum you can provide which will reflect the marriage.Even i submitted around 400 pitcures. if it was arrange marriage and you have taken couple of trips, the boarding pass of that too. But before submitting the applications make sure you have everything because if you miss one paper , ur case could be delayed.More the proofs, much easier for the VO to approve the marriage.