It depends but yeah, that's what I do. If you really want to keep your Pokemon that you've caught and already have Pokemon Bank, it's the best strategy. If you don't have a subscription you could save some money and trade with a friend, but that's quite time consuming (as far as storing your Pokemon, at least).
If you just want more of the same species, you could trade with people, if you're not super excited about replaying the game.
Hope this helps! :)