In addition to being disciplined with your money, keep your debt under control. The less debt you have to pay off near your preferred retirement age, the more control you have when you retire.
It is a good idea to take some risk — both in terms of investing enough of your retirement portfolio in stocks to beat inflations, and thinking creatively about your career. For instance, think about whether your current skill set and college degree can be applied in a field you have not ever considered.
Finally, keep your job skills sharp and up to date as technology and trends change. Doing so could put you in a better position to move into a higher paying role when the opportunity arises.
This also could allow you to transition earlier into a retirement career such as consulting. Having enough saved and current skills gives you the flexibility to plan your exit from the 9 to 5 job. This may even include working only-part time or volunteering.