Illustrative stock photograph; not a Meluvya result or a test of the technique. Photo by Ron Lach / Pexels.
The quick answer
Texture emphasizes or softens surface detail, Clarity changes midtone edge contrast, and Dehaze addresses a hazy appearance. Try one control at a time and check areas that should remain quiet. None is a substitute for a well-focused source photo.
Name the problem before adding detail
“Make it sharper” can mean several things. A knitted sleeve may look too smooth, a building may lack separation from its surroundings, or distant hills may disappear into haze. Applying every detail slider to all three is a poor way to find out what actually helps.
Choose a photograph with one feature you want to emphasize. Also choose a feature that should stay gentle, such as skin or a plain wall. Those two priorities give the comparison a purpose.
What the controls are designed to change
Adobe describes Texture as concentrating on medium-sized detail, Clarity as changing contrast around midtone edges, and Dehaze as reducing or adding a hazy appearance. These descriptions concern Lightroom; similarly named tools elsewhere may behave differently.
Control
Useful first question
Texture
Does the surface itself need more or less presence?
Clarity
Do forms need stronger separation without changing the composition?
Dehaze
Is a veil of haze part of the problem, or part of the atmosphere I want?
Run a three-patch trial
For a portrait in a textured sweater, use the sweater, a cheek and a smooth background as your three watch areas. The following exercise is a way to judge your own file, not a preset or a claim about the stock image.
Start clean. Keep a reference version before these effects. If an existing preset contains several strong changes, compare with those changes disabled where possible.
Try one slider. Move only the control that best matches your goal. Compare the target area and the two watch areas before touching another control.
Reset and compare. Return to the same starting point for each alternative. Keep the viewing size consistent so zoom does not become another variable.
Choose by tradeoff. Keep the smallest useful change. If the sweater improves but the face becomes distracting, consider limiting the edit to the sweater instead of increasing a global effect.
Combine controls only for separate reasons
A landscape might benefit from both clearer distant forms and more visible rock texture. That does not mean both controls need the same amount. Name the second problem after the first edit, then decide whether it still exists.
For a misty morning scene, try a version that preserves some softness. If the hills become conspicuous but the picture loses the atmosphere you liked, the clearer version may be the less useful one. More visible detail is a choice, not an obligation.
After changing Clarity or Dehaze, revisit the overall color and brightness. Adobe notes that these controls can affect more than the apparent detail. Avoid compensating with several unrelated edits before deciding whether the original adjustment was too strong.
Review both the whole image and small edges
At the size you plan to share, check whether the intended feature becomes easier to read. Then zoom in to inspect hair, glasses, clothing seams and smooth areas. Look for a new visual problem rather than rewarding the version that looks strongest for one second.
If detail was never recorded clearly, stop trying to force it out with surface contrast. Return to another capture when you have one. Save the editable version so a treatment intended for a small post does not become the only version available for a larger display.
Common questions
Should I increase all three controls together?
Only if each solves a separate visible problem. A one-control trial makes unwanted changes easier to trace and undo.
Can negative Texture fix every skin problem?
No. Decide what you want to change and preserve recognizable features and surface character. Making every area equally smooth can create a new problem.