A word on mushrooms/leathers...
I discovered thanks to having a baby that the clear plastic baby food containers are very useful.
Clean well (really hot water does just fine), fill halfway with rubble, poke numerous holes for circulation, add your bit of squishy coral, put the top on and sit in the tank for two or three days. Mushrooms, leathers, xenia, etc attach really fast and then you can glue the bit of rubble anywhere you like.
It looks pretty ghetto, but it's only for a few days and it's easier than trying to keep them rubberbanded down ime.