Choose a bath mat that has room to dry
A bath mat needs a clear place on the floor and somewhere to dry. Check those two spaces before choosing its color or pile.

Open the bathroom door and leave it open while measuring for a bath mat. Then open any cabinet or shower door nearby. A mat that fills the available rectangle when everything is closed may bunch against a door during ordinary use. Check the full thickness, including any backing, rather than relying on the footprint alone.
Choose the landing spot
Think about where your feet actually meet the floor when leaving the bath or shower. The mat should serve that area without extending into a busy doorway. A long runner may look generous but can be harder to lift, wash and dry in a small bathroom. Two mats are not automatically better if their edges meet in an awkward place.
Read the product's instructions for the flooring underneath. Backings and separate non-slip layers may have compatibility or care requirements. Do not assume a mat remains secure when the floor is wet, dusty or covered in product residue. Keep it flat and inspect it as part of the normal bathroom routine, replacing it if its backing deteriorates or edges no longer lie properly.
Follow the mat through laundry day
Find out whether it is machine washable and how it should dry. A thick cotton mat, a synthetic tufted one and a rigid bath platform are different products with different maintenance needs. Consider whether you have a suitable rail or drying area large enough to spread the chosen mat as directed.
A spare can be useful when the first mat takes time to dry, but only if there is somewhere sensible to store it. Choose a quantity that supports the laundry cycle instead of collecting several decorative versions. If you prefer a pale color, picture the bathroom after a week of ordinary use rather than only immediately after cleaning.
Feel the edge as well as the center when shopping in person. A raised binding may catch a foot even when the pile itself is low. Online, look for side views and a stated thickness. Once it arrives, test the placement on a clean, dry floor under the return conditions. The mat should make the transition out of the shower easier without becoming another object to step around.