Define as small an idea as possible that needs to be implemented, or pop the latest one off the "stuff to do" stack.
Implement the idea.
Send out a diff of changes to the code that implement the idea for review by a peer(s), manager(s), or pertinent owner(s). This diff should include the changes and text explaining the changes and how they were tested.
If necessary, iterate on feedback from the review and repeat the previous step.
Ship the code.