Gradients: select layers

for the life of me i can never remember how to apply a simple gradient to a single layer. the gradient i apply always alters with the rest of the image. i ctrl+click on the layer, and then try the same on the mask (if there is one). help! my husband is tired of me asking.......perhaps one of you has an easier way??

Ctrl + Click on the LAYER THUMBNAIL itself (in the Layers Palette), should load a selection (marque) around that layers pixel contents only.

Then proceed with Gradient.

heathrowe