When modelling small birds, I find it easiest to attach the body to the end of a round headed pin or rounded toothpick to give me a handle to work on the sculpture. With the body secured to the pin, you can use modelling tools or clay shapers or for air dry clay, damp paintbrushes to shape your work
Compare your rough body to a photograph of a dove or white racing pigeon in a pose close to the one you want to sculpt. Add extra modelling compound to areas that need to be more rounded, and check the body length for the tail length and position. On pigeons, you may want a pronounced breast area at the front and a very short neck. Check your photo.
Add a section for the tail, blending it in to your body. I flatten out a small ball of air dry 'Delight' clay and trim it to the rough shape I want the tail to be, then gently tear the end of the shape to give it the look of feathers. For air dry clay I moisten the tip of the tail and press it gently into place above the rough tail shape I made when I made the basic body shape, blending the top edge of the tail where it joins the body into the back of the dove with a fine damp paintbrush.
The final modelling is placing thin layers of modelling compound for wings. Pigeons or doves have fairly smooth wings when folded, check on a photo to see how they are arranged. Roll out small balls of your modelling material into thin oblongs and curve them into a crescent at either end. If you are using air dry clay, dampen the body of your dove with a damp fine paintbrush and press the wings onto the body starting where the shoulder of the bird should be and extending back to just above the base of the tail. Blend the wings into position and shape with a soft paintbrush (dampened if using air dry clay)
Continue to shape your dove, checking its balance every once in a while to make sure that it is not too heavy on one side, or on the head or tail end. To check it's balance, set it so that it 'sits' on your work surface. It should sit properly without falling forward, backward, or to the side.
If you are using epoxy putty to model your dove, make sure you leave an indentation where the leg wires will fit. You can insert the leg wires into the gulls body when you have the main belly shape finished, and allow the putty to harden around the base of the wires to hold them. If you are using polymer clay or lightweight air dry clay you can add the legs after the main body has set up (air dry clay) or stiffened (polymer clay).