If the yard is small, consider Crepe Myrtles instead of traditional trees. They're impossible to kill, and you control how big they get based on how you prune them. Should prevent foundation issues from planting other trees close to the house.
Instead of decomposed granite, I prefer brick pavers that are on sale at lowes this weekend. The have standard red or tan ones instead of the ugly ones in the link at my location. Less DG gets tracked into the house, which can scratch up hardwood floors. And they're cheaper than flagstone.
brick pavers
As far as furniture, I go the budget route and cruise by Academy middle to end of August when they put their patio furniture on clearance. I'm sure other stores do the same. It isn't the greatest, but you cna replace it multiple times for the cost of the good stuff. Only the stuff I have that gets hit with salt water rusts.
Keep it simple in a small backyard. Round table, 4 chairs, grill, firepit with some benches. All that stuff can be moved around as needed. The planter beds are little more permanent. Try out container gardening before commiting to the beds.
