In order to earn this trophy, you must earn 500 BP by winning in Ranked Matches. The base amount for even a person with 0 BP themselves is 50 so essentially it could take only 10 matches if won consecutively against opponents with a similar level. The only problem with this being that if you lose your points will decrease, and quitting will give you a SEVERE decrease much worse than a loss. Defeating higher opponents will give you a bit more of a bonus, but nothing too great at this point as people are still rather low when it comes to points.
In order to hasten the process a bit, look for single round matches and go from there. If one wanted to boost they could simply set their region to something obscure such as Slovakia similar to boosting other games with matchmaking and given the fact not a ton of people are searching single round matches, you should be in the clear. Don't forget to set the search settings to your area as well as similar rank if you and a friend are in the same rank class shown by the letter grade at the top of the screen.
Either way this will come along with your Reach Rank C trophy as well as your network wins of course. If there's anything you would like to see added, feel free to comment.