I'm pretty sure most people don't use this mechanic: once your in a lvl grab s much money as you can without risking death and go for the door. Then go back to get an other remaining coins. Rinse & Repeat.
here's a suggestion: lock the door that has the save runes in it until you get the item inside that room. Because I accidentally went from the 3rd floor boss to the first room of thr 4th floor without picking up anything in the element room.
Made in 1921 :D (made in China or not :D )