I check it everyday when the price is moving fast but only every other day when it's stable.
Same really. I sometimes don't check the price for days or even all week when it seems to be stable, but if I see activity on here about the price going up or down I keep checking the price several times a day.
I have a SMS alert if the price goes lower than 300$.
This is a good one, you can also try
bitcoin ticker to remind you when Bitcoin reaches certain price, when using iOS devices.