It is easy to make a program that is right, faster. It is difficult to make a program that is fast, right.
— Michael A. Jackson (1936- )

When you work on a solution to a problem, you should first aim at creating something that works. Concentrate on doing it right. Include everything that comes to mind in your design and make it all work together. After you have a design that works, that accomplishes your desired end, then go about the business of making it fast, making it lean, making it fit.

A designer knows he has arrived at perfection, not when there is no longer anything to add, but when there is no longer anything to take away. — Antoine de Saint-Exupery (1900-1944)

Once you have made it right, you will want to eliminate everything that does not directly help your design accomplish its purpose. This includes works of art as well as works of engineering. That book you wrote? Remove all that does not help the story. That painting you want to do? Remove all that does not portray the message of your work. That program you wrote? Take out the bells and whistles that a user will never use.  That life you live? Take out the clutter and excess action. This process make take some time. The time you spend will make your efforts worthwhile.

The result of a year’s work depends more on what is struck out than on what is left in, on the sequence of the main lines of thought, than on their play and variety. — Henry Brooks Adams (1838-1918)

Strive to make every one of your designs a focused piece of work. Make it right, make it strong, make it clear, make it simple, make it meaningful. Nobody will misunderstand your design when you do that.