Principles
Always code for clarity, not efficiency. Choose variable and function names carefully. Be verbose rather than terse, and parenthesize expressions to make them clearer. Write your code for the reader.
Limit the scope of constants, variables, functions, and subroutines as much as possible. If you have the choice, always use a local object in preference to a global one.
Use explicit type conversions (CInt, CStr, and so on) when assigning between different variable types.