It is important to have the right amount of insulation in your attic:
The minimum amount of insulation you should have in your attic ranges from 8 – 12″ depending on your insulation type. Spray foam could need less. Adding insulation over what you already have is an easy solution to cut your monthly energy use and increase your comfort in your living room.
Other things to look at while in your attic:
There are some other things to look at in the attic while you are there. Make sure there are no vents from dryers or bathrooms that vent into the space. You want to keep your attic as dry as possible. Adding moist warm air into that space only leads to problems. Also, check for any critters that have decided your attic is a nice warm place to hang out. On a recent energy audit I found what looked like multiple nests. This is not uncommon as your attic is a much nicer place on a cold winter night to sleep. Check to make sure you have complete coverage in the space. You want the entire attic area insulated. You also want to make sure the attic is as air tight as possible from your conditioned home.
Last check before leaving the attic:
As you are leaving the attic, make sure your attic access is covered with insulation.