Step 1: Search good reference for your paleoart.
Paleoart is a serious business! A good restoration need good scientific reference. In this case the art of mister Scott Hartman is truly usefull.
According with the discoveries made on the dromeosauridae clade, Deinonychus was feathered. For this reason some reference of wing anatomy are recomended.
With this material make a realistic lineart of Deinonychus.
The pose is very important so try to portrait the animal in a pose as natural as possible. In this case the head aligned with the backbone and the tail held high give a sleek/agile predator look.
Step 2: Fill the outline with a light gray background to make a plain silhouette of the animal.
Step 3: Add shadows using a scale of grays to give a 3D impression to the body.
Step 4: For the coloration I chose the mimetic palette of a local bird here in Sardinia a partridge, a ground-nesting seed-eater galliformes native to Europe, Asia, Africa, and the Middle East. Coloration is applied using a Photoshop layer with "multiply" filter.
Step 5: Add details of the eye, the naked skin, the feathers and partridge-like pattern on the neck and on the womb.
Enjoy the final result!