I have what I think is a good idea. I hate practice pvp because I always win. I'll win twenty in a row, then go to ranked and it is so much harder and totally different. The people in practice are usually just testing things, they flee often, and many times are just trolling. It isn't good practice.
I thought it would be really cool if when signing up for ranked, you could pay crowns or something, to buy immunity. You would have to do this before even starting the match, but if you did, win or lose, your pvp points would not be effected. Your opponent would still be the exact same as they would have been otherwise, losing or winning points (unless they had also paid to be immune). That would allow someone who was more serious (especially high levels) to actually be able to practice. Also, if it cost crowns, the immune player would still take it seriously because he/she paid to be in the match, so you wouldn't fill ranked with trollers. Tournaments allow you to do this a little, but because they are timed and everyone in them is balance and spam mana burn, it is a very different type of play and isn't really good practice for the real thing.