My wife has been wanting a deck for years, so we finally had one built this summer. In retrospect, I should have done it myself, but that's another story. The current story is that I'm looking at putting in some flagstone for a patio next to it or just as a landing for the stairs. I put weed block down under the deck and covered it with white pea gravel, and the whole thing is edged with cream chopped block (well, I'm almost done edging...). Here's a photo of the (mostly) finished part. I'll be finishing the outside edge and adding some grass up against it soon.

That being said, I'm going to use cream or white flag stone to match, and if I go with a patio instead of just a landing, it will border the cream chop on 2 sides.

For base, I've heard 4" of compacted decomposed grantite, or 4" compacted gravel with a 1" bed of sand over the top and a landscape fabric between them. Thoughts?

Also, what should I put between them? If heard decomposed granite or polymeric sand. What colors would go well the white/cream stone? Should I plant some grass seed between them? Ground cover thyme?

I was also thinking of edging with more chopped block along the remaining 2 sides for consistency.

Only advise I can give is against polymeric sand. We used it on our flagstone patio at our previous home. It was nice for about 1 year then started degrading. It really didn't hold up as advertised. We tried to clean out and fill in weak spots with more sand but it never would bond/ match right. Eventually gave up and cleaned it all out and used a traditional mortar/cement in the gaps.

When my landscaping guy came out to discuss options, he even admitted they stopped installing it in large patio applications as it didn't hold up like they thought it would. Great for small areas, or small gaps. He is who recommended a traditional mortar/cement in gaps.

How big were your gaps?

They varied, but anywhere from 1 inch to 3-4 inches. I would think less than 1inch would probably be okay, but even the 1 inch gaps after about 5 years the polymer had worn off and the surface was breaking apart and being weathered/ weeds starting to pop through.

Ok. Everything I've read says it's best on 1.5" or less...

had a 192 sq ft patio built last year. Original "contractor" if you could call him that, used polymeric sand and crushed granite. Patio was a total, unstable mess. The original guy refused to fix it and claimed it was exactly what I ordered. After dealing with him for over 3 months I finally had another guy come out and rip it out and reset everything in concrete and mortar. This ended up costing me another $2000 but that patio has been great ever since.

Only problem I have had is the patio doesnt completely slope to drain the water. I'd suggest making sure it does slope to some degree and even install a simple drainage system that will drain the water off the patio to the yard.

Gator dust in between

From everything I've researched, the original guy probably didn't compact the DC base or level the stones once they were set. You need to add some kind of loose-ish layer of sand or DC under the stones to fill in any voids between the stone and compacted DC base and then tamp them into place, otherwise it's like setting them on hardened concrete, and you only get support where you have contact. If you don't add this extra sand/DC, eventually you get uneven settlement and/or lose stones.

I've considered a mortar base, but I hate working with concrete flatwork. At least with gravel and sand, I can always rework it as I go. I also want some kind of sand or plants between my stones. From what I understand, you have to go with mortar if have a mortar/concrete base, and there'd be no possibility of planting because of poor drainage and little to no soil.

As for slope, I'm planning on 1/8" per 1'. My problem now is that it slopes too much. One corner is about 4"-6" higher than the opposite corner where my deck stairs land, and it's only 10x12ish. Once I excavate, I'm going to set some tall chopped block around the edges to keep the soil up against the foundation at its current level while dropping everything else for the patio. I'm also going to weed block between the chopped block and house and cover with gravel to match what's under the deck. That should cover the drip line of the roof and prevent erosion.

My problem is that 6" of drop plus 2" of gravel already leaves me at 8" of chopped block, which is my max height, so I don't have a good way to set it. I'm thinking of getting 4x6 dry stack to set around the base of the patio in the highest areas and then setting the chopped block on top. I'll drill holes in the chopped block and dry stack, fill them with grout, and set rebar in them so the dry stack acts as a footing and the chopped block won't just fall over.
I'm still trying to figure out how to slope this mini retaining wall to be consistent with my existing grades though.

What is that?

http://www.alliancegator.com/products/polymeric-sand-and-dust/gator-dust/