Easy pillow cover tutorials are all over the web, Pinterest alone has a ton. I usually make an envelope style cover, that way I can remove it and change my look, no hassle. However, I realized that I never, not once, put the cover back on again! So this time I've just covered them standard.
I won't bore you with a bunch of directions, if you don't sew, ever, you probably won't be reading this!
Our ginormous sectional came with super ugly throw pillows, which I have just found time to cover. I picked up some Waverly Sun n Shade Fabric, it's indoor/outdoor. I normally would not have used it inside, but once I felt it, I was surprised to find that it isn't even scratchy and I think it'll hold up better with 5 kids and the pooch.
So in pictures, here's what I did...
lay the insert out and cut around it
wrong sides together & zigzag stitch 3 1/4 together
turn right side out and stuff your form back in
fold in the opening and pin,then straight stitch it closed.