A repeat with no seam, from any system.
Pattern mode takes whatever is on the canvas and builds a tile out of it. Export one tile, or lay out up to a 3×3 sheet. Use the sheet. A single tile tells you almost nothing about whether a repeat works; three by three will show you the grid you did not know you had made.
Mirror reflects the design into a block, so every edge meets its own reflection. It cannot fail. It works for any system at all, and the price is four-fold symmetry that the eye picks up eventually.
Wrap sends a mark that runs off one edge back on the opposite one. The design stays asymmetric, which usually looks better. It needs to be able to measure where every mark is, which is nearly always possible.
Pattern mode uses the first frame. There is no way around it: a tile that moves is not a tile.