Keep the test consistent
Use clean running socks of the type and thickness you expect to wear. A thin shop sock can make a shoe feel different from the thicker pair you use on trails. If you regularly use two kinds, bring both and test them separately. Do not change socks and shoe size at the same time, because you will lose track of which change improved the fit.
Put the sock on carefully before the shoe. Smooth folds, position the heel and check that a seam has not twisted under the toes. A small wrinkle can distract you from evaluating the shoe itself. Try both feet, with your usual insoles if they are part of the intended setup and appropriate for the shoe.
Move beyond standing still
Fasten the shoes with ordinary, comfortable tension and walk around. Notice whether the heel stays settled, the toes have comfortable space and the upper presses anywhere. Use the shop’s permitted test area rather than inventing a risky movement between displays. If a short jog or ramp is available, ask how to use it and compare the same movements in each candidate.
Pay attention to what changes when you turn or walk down a slope. A combination that feels roomy while standing can allow unwanted movement; another may feel acceptable until the toes approach the front. Do not assume a sock will solve a shoe shape that is clearly unsuitable. Changing thickness is a comparison to investigate, not a way to force a purchase to work.
Remember the complete combination
Record the shoe model, size and sock used for the better fit. A label alone does not capture the result. If you buy another pair later, check whether the sock construction or shoe version has changed before expecting the same feeling. Keep the return conditions in mind and conduct any further trial within those conditions.
At home, repeat a brief indoor check with the intended socks before taking the shoes outside. If something feels wrong, stop and reassess rather than trying to overcome it with tighter laces. A useful fitting ends with a combination you can describe and reproduce, not simply a size that seemed familiar on the box.
