A simple soaring eagle figure. Designed by me, in 2022.
I use red dashed lines to represent valley folds, and green dashed/dotted lines to represent mountain folds.
Begin with a preliminary base (colored side out), with the open points facing down.
Fold each of the upper edges to lay flag against the center line; crease flat, then unfold. Repeat behind.
Fold top edges down to lie flat along creases made in step 1 (as shown at right edge); crease, then unfold.
Similarly, bisect the area between each fold from step 1 and the vertical center fold. Basically, instead of dividing each vertical triangle in half (as you did in step 1), you are now dividing it into 4 parts. Each time crease and unfold. Repeat behind, on rear side.
(Note: yes, you can do this just by re-halving the folds in step 1 before unfolding. But I find it hard to keep the inner layers from bunching and becoming uneven that way.)
Carefully pull the inner layers of the preliminary base out, as shown at right. Repeat on the left side of the model as well. You will re-fold/reform them in step 4, below.
Re-fold the layers you just pulled out (step 3) around the central part of the model, so that the two side layers are now outside of the central portion. (See the illustration, at right, to see how the layers should finish.)
Fold/re-form the layers the same way on the right and left sides of the model. The newly formed right/left layers should be on the outside both on the front side and the back side of the model; front and back of the model should look the same when this step is finished.
Settle all layers/crease lines and crease/flatten into new shape.
Mountain fold the outside edge of the central portion along the existing crease line into the open center of the model, narrowing this portion of the shape. Make the same folds for both right and left edges on the top layer.
Fold the same outer portion of the center (lower) level up and around - much like step 5, but in this case you aren't folding into the center but instead wrapping up and around the upper central layer.
It may be helpful to first fold the lower portions into the center and crease (just like step 5), then unfold and re-form so the folds go around the upper layers instead of into the center.
When this step is done, you'll see simple "tail feather" patterns on the top central layer as shown in the drawing on the right side.
The left side shows where the fold will be made; the right side shows the model once the fold is done.
Valley fold center top peak down to meet base of broad triangle, as shown in diagram. Crease firmly.
Valley fold center peak back up, as shown. Fold should be roughly 1/3 of the way along the section folded down in step 7, so that the sections of the new top layer "above" and "below" the top horizontal edge are roughly equivalent. Crease.
Fold as shown, narrowing the head/beak portion of the bird and shaping the "shoulders" from the folds made in steps 7 and 8.
The left side shows where the fold will be made; the right side shows the model once the fold is done.
Turn model over (the side you were working on is the bottom). If desired, pinch "beak" to reshape slightly and/or add a dab of glue between head/shoulders and top of body to keep model from pulling apart. (This may be necessary depending on the kind of paper used.)