I have started using old bed pillows, you know the poly batting filled ones? You cut the batting up with scissors, or your rotary cutter and stuff a bag, sew the top closed and Viola'!
I found out that the stuffing , once cut up, doesn't stick back together again and remains soft & fluffy after one of my favorite pillows exploded in the washer at the Laundry mat. There was a snag in the tub & it ripped open the case... after I dug all the stuffing out & took it home I had to make a new case for it... Genius!!!!! I re-did all my pillows that turned lumpy after getting washed. They stay fluffy, wash after wash... Oh, and I used washed canvas painters tarp for the cover, it's a neutral color, can take a beating, softens up nice ... I used the tarps for slip covers on the couch also, dog slobber, grand kid snacks, it all washes out. And they're relatively inexpensive.