On my travels along the Sikh path I started out believing similar to A_seeker. I thought the gold standard of Sikh practice was to sit in the dark and repeat Waheguru until something magical happened. I would try to have a constant chant of Waheguru, Waheguru in my head all the time. I sung it, I listened to it, and I believed very hard that some miracle would occur.
All that happened to me was I became numb and dumb. Maybe it's different for other people, but my mind was so full of parrot chanting that I couldn't really *listen* to God, I wasn't *singing* (my thoughts and actions weren't in harmony with God) because I wasn't paying attention, I wasnt believing. I was playing telephone hold music in my brain!!
My personal practice turned a corner when I stopped mindless chanting of a word and started to focus, contemplate Gurbani in less literal terms, and let my mind be filled with love and awe instead. When I started to really pay attention and use my discerning intellect to observe and get a sense of hukam (listening), then try act in consonance with that universal will (singing), things started to make a lot more sense, I became far more useful and dutiful, and I got more glimpses of the Whole and the exclaimed "Wah!".
But this is just my own experience.