Idle boosting method
Not the fastest, but it lets you skip the need for multiple other accounts to boost with. Normally if you boost with someone else the game has a anti-boosting feature where you can't face the same account twice in a row which creates this achievement to be a lot of work with a lot of accounts needed, however, there is a single player way to do this that could be completely idled if needed.
Go into single player ultimate team. Make sure you are facing the single player championships as this mode will not cost you any coins etc. Once you go into there just advance using A until it starts another match and let the CPU beat you. I would get about 100 coins per match and enough XP to rise each level in about an hour. So this method will roughly take 25 hours or so to go from start to finish, but it can be completely idoled if you have a turbo controller that can press a on slow speed. (You don't want to do fast speed, because it will bring up the cancel search menu and create a loop).
Is it the fastest method ? No, but it is efficient and allows you to be able to do other things while it is running. The biggest advantage of this is no need to make a million accounts that you and a boosting partner would need to do otherwise.