In the absence of 'coin control'
SOME FRIENDLY ADVICE
.. for people unfamiliar with PoS coins & 'minting'...
One of the important factors which controls the success of minting is the size of the wallet-block attempting to do the minting.
Hence, your best method of doing this is by the size of the 'payout' you set from your pool to your wallet.
Without better data, and being unable to match the data to all of your various rigs anyway, my best suggestion is that you tweak your payouts so that you're getting between 4 and 8 payouts/day into your wallet.
Another important thing to note is that if you make even a
tiny payment
out of your wallet, it will re-set the 'age' of the whole block it's taken from - so resist paying small 'tips' from your account until you DO have a coin-control wallet & learn how to do it properly. Unless of course you WANT to lose valuable mint-blocks
THIS is the current best online explanation of how coin control works (HoboNickel Wikki)