If hardwood planks lie perpendicular to a tile floor (short, cut ends border the tile), it’s usually best to border the wood in its own material (1-2 rows depending on thin/wide plank width) before starting the tile. The wood border caps the cut plank ends, and also provides a continuous straight-edge border for the tile installation.
Some people choose not to use a border to cap the cut plank ends if the adjacent material is large enough to function as it’s own straight-edge in contrast to the cut planks.
If the adjacent material will be set at an angle, it might also be decided that that material also include it’s own border. Some people prefer no emphasis (such as a thin decorative strip) between material borders and simply want to lay a low-profile bead of silicone caulk into the joint between the materials. You’ll need long straight-edged borders to keep the emphasis off the joint or awkward short-cut edges of either material.
If materials will be meeting each other at any kind of angle (i.e. 45 degrees), this installation will also require some kind of “straight edge break” border between the change in pattern or direction–even if continuing with the same material.