Hi Boujasim,
In my case, my husband came over here in Canada and lived together for two months after marriage. Then we submitted the file.
Apart from necessary forms, I had an extra things like,
1. Hundreds of photos, for before marriage, marriage, honeymoon, after marriage in which we are together with family and friends at different well-known places, having dinner together with friends (including canadian friends).
2. Copy of our inbox showing our contact before marriage and after marriage
3. Phone-bills (I used startec and printed the call-history which was worth more than 1000$)
4. We lived in my flat and took co-tenanacy letter from the owner
5. Marriage invitation card
6. Receipt of marriage-hall
7. Tickets for Honeymoon, receipt of hotelbill
8. Statement of bank-account together (we opened one account so that my hubby can use debit/credit card anytime in case I am not with him, but it was really useful to show that as evidence)
Above all, some people take support-letter from their family/friends who write about the genuineship of their relationship.
Hope this helps,