Look at three things: leaves, stem, and roots.

Healthy leaves are a vibrant, even green. Skip anything lime green, yellow, spotted, crispy at the edges, or wilting. Dark green with purple stems often points to cold stress or a phosphorus issue, not a healthy plant.

The stem should be thick and sturdy, not thin, stringy, or darkening near the base. A black stem is a dying clone. Walk away.

White, fuzzy roots are the sign you want. Brown, black, or slimy roots mean rot. If the cutting has been out of the mother more than 14 days with no visible roots, something is wrong and you should pass.

Check for pests, white powder, black spots, or a musty smell. Healthy clones smell fresh. And always ask whether the clones were HLVD tested before you buy. It's the single most important piece of information a clone seller can give you.