Set An Alarm
Like in the morning? No don't do that! Sleep as long as you possibly can! You'll need every ounce of energy to get through the day. What I mean is I use an alarm as a way to get my daughter to stop asking for things constantly. If you know my daughter, you know she LOVES to eat and would pretty much eat all day long if I let her. So rather than having her yank on my pants and beg INCESSANTLY, I tell her she can have a snack when the alarm goes off.
I use the alarm trick with many other things as well like clean-up time, bed time, when we get to go outside, etc. It really works. My daughter will ask to do something and then will say "Set an alarm." Then she won't ask again. Or if she does, I just remind her that we have to wait for the alarm to go off. It kind of turns it into a game. Maybe it won't work for your kids, but it's been amazing for us!