In a meaningful interface each label and control needs to be given a considerable amount of thought. The layout and combination need to have a clear purpose and meaning to the user. He needs to intuitively know or recognize how it is to be operated and its function. Label each control so it is clear to the user what it controls and what its intention is.
Use meaningful codes, as they are easier for the user to both recognize and recall, likewise for mnemonic codes and accelerator keys. Single letter mnemonic codes will be easier to remember if one uses the initial letter in the option name.
Use familiar units so the user recognizes the information without having to estimate its value in a known unit. If translations are needed to another unit, the computer can easily do this.
Use conventional colors to display data, but never use color alone. If there is a color convention that is generally recognized in the users environment, apply it. Here is a list of recommended color conventions: