i feel there are tons of different playstyles within kkdd and kddk, and you should just do what you feel is the best for you, even though i recommend kddk for everybody
the way i play is kddk, i feel it's really good to have the option to press both colors with both hands, and you can play with both arms/wrists and/or fingers. it's the standard way as for the taiko drum (on arcades) you hit the middle for
lower pitch sound (don) and the outer for the
higher pitch sound (katsu)kkdd is probably faster to learn overall, even for higher skill levels. but will struggle with stamina for
monocolor streams/bursts (usually, ranked maps aren't like this example) and overall accuracy at high star ratings (even tho there are players that can get really good accuracy with kkdd)
about tips for kkdd, you can maybe watch some plays of kkdd players like
applerss that have handcam, so you can feel a bit of how it is to play like that and how they do to play really fast and with accuracy
i would probably play like this if i were kkdd (1234 above qwer, just as an example): if there is a color that repeat, i press with the other finger but always would reset when pressing the other color, so for
kkddkdkdkkkkddddk i would play like:
12431414121243431the way to improve this would be to alternate more instead of repeating the same finger i could play like this:
12431423121243431hope this helped somehow
maybe too much text as awlways...