I found the idea of a High 5 chart, which worked for us at that age. My dd, now 6, and my ds, 3.5, know that they have to do the 5 things on the chart every morning. There's still some grumbling, but it works better as a visual. I update it every few months as needed, and I have them help me make it as a craft project.
Basically, it's a hand print with something they have to do on each finger. Right now, our morning High 5 "chores" are: Get Dressed, Eat Breakfast, Help Empty Dishwasher, Brush Teeth, Read Bible with Mom. Our evening one right now is Clean Up Toys, Potty & PJs, Brush Teeth, Drink Water, Reading Time.
These are the things they must do every day. Without reward or consequence. We just don't do anything else until these things are done. I have to do them with them until the routine is established, but once we get there, they know what is expected of them and just do it. Okay, if they are really struggling with their attitude and throwing fits about doing these things, then we address it with discipline, but most of the time, it works pretty well.
Also, give them and you some grace! There are definitely days when this is not at all how things go, especially if I've been up in the night with one of my boys (ages 3.5 and 1). But if you set the expectations, then they know when the job is done and so do you.
Hope this helps a bit! I'm off to check out some of the other resources listed in this thread :-)