So I finally finished the dog bed I've been working on for over a month now (I've been trying to avoid the 100+ Texas heat but it just wouldn't go away!) It was based on dmanar33's farmhouse dog bed (linked below) and I just made it larger for our greyhound, Daisy. It's far from perfect but it's been another good learning project for me while practicing before I start our desperately needed King bed.
The bed was made using 2x8 for the internal structure (with one 2x4 center "slat"), 1x6 and 1x8 boards for the surround, with 1x2 as trim and 3/4" plywood for the cushion base. It is rather heavy but can easily be moved with two people. This was my first project using my finish nailer ($16 at Harbor Freight) and it was worth every penny! I can't believe I never picked one up before.
For the cushion I tried to find a cheap, thin 3" futon mattress on Craigslist to cut up (as I've done before), but after 2 days of looking online I ended up settling for a $12 full size foam mattress topper from wally world. I folded it in half and wrapped with some thick batting I had laying around so the cushion ended up ~2" thick. And for the cover I used Ana's doll mattress tutorial with some wally world Chino Cotton curtains for $16 as fabric (thick, durable, cotton and cheaper than anything I could find at the fabric store) and it worked out great! I left one end open to put a zipper into once I pick one up, so right now it is like a large pillow case, but it works just fine.
I'm very happy with the total project and I love that Daisy (~75lbs) won't be breaking it anytime soon. She has plenty of room to stretch out and it looks much nicer than the old lumpy "giant pillow" style dog bed on the floor we had before.