Inspired by Ryan Kinglien's "Bust with Flowing Hair" Tutorial from Gnomon, I've been doing "Hair Studies", modeling one hair style after another on the same bald bust. One of those styles was braids. Because my roots are in clay, I adapted a clay based method. While not as elegant as the Alpha based method I've subsequently found, it's simple enough for the ZBrush novice.
1. Load the Cylinder 3D Primitive and turn it on end. In Initialize set X to 10, Y to 6, and leave Z at 100. You now have a long rod with an oval cross section. Subdivide 4-5 times. Adjust the orientation in the Preview Window.
2. In Deformation, Twist to the right 8-15 times only on the Y axis. This example is 10 twists, suitable for my needs. More twists will create the illusion of a longer braid.
3. In Deformation, apply Inflate on the Y axis to a value of 50. If you twisted the rod more than 10 times, Inflate to a lower value. If you used fewer twists, apply a higher value. Subtract or add roughly 10 points for each twist over or under 10.
10. Apply Balloon Inflate on all three axes (X,Y,Z)to the same value, in this case 50.
4. Convert to a polymesh and Unify. Texture as desired. I used the Standard Brush, Damian Standard and accented the grooves with the Slash 3. This is one (longitudinal) half of the braid.
5. In SubTool, Duplicate and then Mirror the duplicated half braid. In Deformation, Offset the new half to create full braid. Merge in the Subtool Menu.
6. Load the Merged Braid. In Deformation, Unify and Taper.
7. Append a Zphere to the tapered end, scale the sphere down and enter ZSketch. Hit Edit. Use the armature brush to add a tuft of unbraided hair. Hit A to preview Skin and play with the texture. Snake hook is nice for an added bit of detail. Add Universal skin. Delete the ZSphere and append the skinned tuft. Merge, load merged braid, finish detailing.
Here is the bust with appended braids, crown hair made in ZSketch: