Thanks to Chantel for this Frugal Baby Tip!
I know everyone says tuck, tuck, tuck! but that does NOT work at our house. I say, "Untuck and be free!" Just kidding.
No really. I do NOT fold our prefolded diaper and tuck it all the way into the velcro cover. I lay it flat on the cover, put it under baby or toddler, bring up between legs, overlap diaper edges at both sides of waist (the cloth surface against cloth surface helps to hold in place), and then, when I fasten the cover, I adjust the legs so that some of the diaper is out. Just a fraction of an inch. It does several things: creates a better seal around the leg opening; creates a better fit for slender-legged babies; keeps all of the bm on the diaper; and keeps the elastic off baby's leg (no marks).
We don't have urine leaks by staying on top of changes. Only on occasion, when he's been "storing up" or we couldn't get to a change at regular time, do we have any damp clothing. You can still trifold another prefold to double and have it all inside. We've done it from the beginning and I almost never wash covers for poop leaks.
P.S. You can still fold down the top or fold in the top side edges a little if your baby is smaller; it'll still reach around the waist to overlap. That's a good way to keep the diaper from shifting so much in the cover.
Another thing to do to get additional layers while using this method is to use a doubler, a smaller diaper as a doubler, or just a double diaper folded as mentioned above.