Only call matching memory management functions. Do not mix and match routines. For example, when you allocate a buffer with malloc(), dispose of the original pointer with free().
When programming in C++, consider using smart pointers provided by the boost library to help correctly and consistently manage memory.
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
For example, glibc in Linux provides protection against free of invalid pointers.
Use a language that provides abstractions for memory allocation and deallocation.
Use a tool that dynamically detects memory management problems, such as valgrind.