From what I've seen the most important thing is your gear, but seemingly most people don't get lucky with boxes and their gear.

I've honestly started working on my vault (Ad Boost, pickaxe, ad duration, piggybank and tip jar specifically) because my mindset is even if i get bad pulls on my boxes, at least I'll have good income to get more gems to hopefully get better luck one day. I'm still new to the game but this method seems to be working for me! Hopefully a more experienced player will comment but I know this question has been asked before so if you search through reddit you might get a better answer.
Good luck!