Masking

I opened the pain vest i had created into a new document. I clicked on "File" "Place" and i chose a design from my documents. To make transfer my vest in front of the pattern, I selected the vest and clicked on "Object" Arrange" "Bring to Front". Then I moved the vest onto the pattern where i wanted it to be placed, so that my vest has some design, I did this with the selection tool.
I wanted it to mak my vest so i clicked on "Object" "Clipping Mask" "Make".