we applied at a difficult visa office (accra - 40% refusal rate) so we left no stone unturned. we sent in 417 pages of communication evidence, including phone bills, skype logs, email inboxes, printed 1 email per week of our relationship, text messages, postcards, letters, greeting cards.
we also sent 250 photos of us on various trips to visit each other, as well as pictures of me with his family and friends. we also sent screen captures of him chatting with my friends and family on skype.
additional evidence we sent were facebook screen caps with comments from friends on our wedding pictures, the screen caps of when our relationship status changed, print outs of a forum i go to where i told everyone about our relationship as it developed, pictures of gifts given to each other, with receipts if we had them. pictures of the scrapbooks i have made from our trips. evidence of the trips such as boarding passes, hotel receipts, tickets from events we went to together. receipts from our wedding and reception etc.
all together, our application was 640 pages with 250 photos. so far so good, as he was scheduled for an interview a week after accra received the package, and now his interview is on tuesday. processing for accra is 10-22 months, so we think our application and all the evidence helped to speed up the process. we were not asked for any additional documents, and the only thing he has to bring to the interview is proof of our communication since the application went in.
most people will not need as much evidence as we sent it, but because i was divorced with children (he was a bachelor), we are different races, and our visa office is tough, we felt better to be safe than sorry.