Hey there... I like the black & red cards for the lower leagues (and especially in low mana cap) battles.
Check it out over here: https://www.splintertalk.io/splinterlands/@mrtoking/how-to-guarantee-a-win-in-low-mana-battles
I've also got some great (yeah, ok, so I'm biased) tips/plans for growing a brand new account over here: https://www.splintertalk.io/splinterlands/@mrtoking/how-much-can-you-really-make-playing-splinterlands
Good luck with your own adventure.