all the suggestions given so far by softies will help in one way or other.'
here are some more ideas. take what is useful to you.
- some degree of independence will help. by independence, i mean that the left hand snare accent is not very dependent on what the right hand is playing on the hihat. experiment hitting snare accents on any 8th note subdivision while keeping a upbeat or downbeat accent on hihat.
in the longer term, drummers often practice polyrhythms to improve their independence.
- interdependence helps too. when you play the normal downbeat accent, you are accenting the hat same time u play your left hand snare accent.
USADrummer's suggestion is a good start, evidents good when u have more time.
one more is practicing unison notes. hit right hand hi-hat ghost notes, and left hand snare accents at the same time. try them at a slow speeds at quarter note value. if u need to assess, switch off the metronome and focus on hitting each set right first.
- posture is another one. when you play the upbeat accent, assess your balance and posture. if you feel weird or shoulder, one side of your waist or wing feels strange. it should not be the case. you should be able to move naturally while playing any groove.
u may shift centre of gravity when playing bass drum notes, thus affecting what your hands are playing. check that too.
- finally, you know how a downbeat accented groove feels like, so it feels natural to you.
but you may not know exactly how a upbeat accented groove will feel like. so check out recordings/songs of upbeat accented grooves. then sit down and experiment on the drumkit, and try to recreate the feeling. you may even end up with something different, maybe more like a linear drum groove.
in any case, every comfortable pattern that grooves leads on to another good thing. so keep going in that direction.
cheers