Alright, so here's the basic setup.. Three sections, one intake, one refugium, and one output. The intake is where you put your skimmer and the end of the overflow. You put your skimmer there because that's where the most gunk will be. The overflow mixes all the oils and water which is what your protein skimmer loves. Next comes the refugium. In there, add the macros and whatever else you want. You'll need to have a light over it, preferably 6500k. I don't have sand underneath mine, but you can have it. I have chaeto, dragons breath, live rock rubble, and my drag plugs down there. It's output is at the end and is the most filtered water. It has pods in it, and is ready to go into the dt. You put your pump in that section along with a heater but you can also put the heater in the intake. And that's basically how a sump works! Here's a pic of one..
1 tip that helped me is to keep it simple. I used nylon tubing and a directional u-tube to follow that.. Works very well.