My hill climbing style depends on the hill. For short, sharp hill I like to power up them in a high gear, standing up if I need to maintain my cadence. On longer drags, its a lower gear and I mix it more standing and sitting and even the latter I change sometimes sitting more upright so I can use different muscles. Easier said than done, I also like to change up when I stand up or the climb eases off as I hate running out of gears. Mostly however I just ride them and tactics are variable or go out the window.