I've only done three - Brazil, Russia and Turkey.

I learned my lesson as to not trying to do it myself with Brazil. As my flight date got closer and I still hadn't received it, I learned American would charge me $750 to change my flight. Fortunately I didn't have to avail myself of that service.

I just paid my money to a facilitator for the Russian one. Quite a lengthy form to fill out, $$$, and mailing and waiting. However it went very smoothly, with the visa coming back to me exactly when promised.

Turkey has a completely different approach. When you arrive, at the airport, you just give them a $20 bill and they put the visa in your passport on the spot.

Good luck to you. Brazil was very interesting to visit. I'm sure you will have a fine time after you've struggled through this.

Romelle