Grid symmetry

You can automatically create a symmetric pattern by selecting one of the Symmetry options from the Grid menu. You can have Normal (S) Symmetry, Dual-Symmetry (Dual-Symmetry only works if you have a square puzzle), left/right and top/bottom symmetries, Dual-mirror symmetry (which combines left/right and top/bottom), and maximum symmetry. Note that the last two options will restrict the lengths of possible word slots that it's possible to have in the grid (e.g. a 15x15 grid can only have odd-length long words over 7 letters).

This pattern shows Dual Symmetry:

Whereas this one only has Normal (S) Symmetry: