What are some C++ programming techniques and examples that should be discouraged or avoided?

Scott Meyers mentions a lot of pitfalls and how to avoid them in his series of books (http://www.aristeia.com/books.html) This is, hands down, the best resource for learning best practices in C++

1. Using void main() when the standard clearly says int main()     http://users.aber.ac.uk/auj/voidmain.cgi 2. http://en.wikipedia.org/wiki/Dangling_pointer 3. Using macros when you could use const.     http://stackoverflow.com/questions/319452/are-all-macros-evil 4. Writing compiler dependent code     like x= ++a + a++ + a++ 5. Using age old Turbo C++ in place of standard http://gcc.gnu.org/! 6. (GCC specific) not using -Wall and other important options     which can detect common mistakes. 7. Forgetting the 'delete' when using 'new' in dynamic memory allocation. 8. Unwarranted use of global variables. 9. Not using standard library.

Using unspecified numbers of arguments in functions.

Using pointers correctly and carefully remembering to deallocate the resources to which they point at every possible place they go out of scope, including when catching exceptions. This is bad because you should just use a boost:shared_ptr<T> and save yourself all the hassle.