theres really no reason to do anything other than sticking to a deck and practicing, seeing as you're on this forum I assume you dont just pick 30 random cards and turn it into a deck. You can do it with a sub 50% win rate, theres really no sort of magic trick to it. People just make better choices than others, resulting in a better win rate combined with playtime that's how people reach top ranks.
I know basically 99,999% of the gaming community blame everything on bad luck, and how stupid luck is etc. But hearthstone isn't about winning individual games its about making the best decisions so you win more games. learn to accept that, and dont turn it into a blanket excuse, that's going to help you improve and enjoy the game a whole lot more.
If you enjoy playing wacky decks with deplorable win-rates, learn to accept the deplorable win.-rates.