If you have cleared the site, plant in the open.

Open plants are a lot harder to defuse unless you have smokes up.

Time and again you see people planting in some corner even when site has been cleared and then losing the round cos the defenders can just stick the bomb from cover.

Remember:

Safe to plant means its safe to defuse too!!!

Default is usually not the spot you want to plant if you can avoid it.

EDIT: Default spots on some maps are fine. They are fairly easily defendable.

The biggest offenders are both sites on Split, Fracture A site, Bind B site, Icebox A site, Haven C site.