The Lower Deschutes is fishing well, with a noticeable increase in good dry fly action in the evening. The Magic Hour is a real thing on a warm summer night, and worth staying for. Or better yet, worth just going down for on purpose. 
In the evening you will find a mix of Caddis, Pale Evening Duns and Pale Morning Duns and Rusty Spinners. 
Here are some flies you want for sure on the dry side: Purple Haze, X Caddis, Iris Caddis, Fin Fetcher Caddis, Silvey’s Edible Emerger, Keller’s Caddis, Yellow Sparkle Dun, Drymerger, Quigley’s Half Down Dun and Yellow Parachute or Extended Body Cut Wing Duns for the bigger PED’s. 
Throughout the afternoon you might run into some rising trout in an eddy or off a shallow riffle seam but count on your nymphing skills to take the majority of the fish. Euro Jigs, Perdigons, Stonefly nymphs, PT’s, Soft Hackles, Micro May and a whole ‘lotta Caddis Pupa. Tan #16, Olive #16 and Grey #18 will be good choices. Fish the grey pupa near weed beds where the Little Western Weedy Water Sedge hatches originate. 
Early July usually means a few early steelhead in the lowest stretches of the river coming up 10 or 12 miles from the Columbia. These are fish that are hot and love a swung fly like a Freight Train or Green Butt Skunk. Watch water temps this week though, as the heat returns to Oregon in a day or 2.