No. 1: Save More
To ensure a comfortable retirement, you should save as much as you reasonably can, starting as soon as you can and continuing for as long as you can.
No. 2: Cut Your Investment Costs
In most walks of life, you get what you pay for. Keep your investment expenses low.
No. 3: Rebalance Your Portfolio
Rebalancing means you sell back those asset classes that have appreciated the most and put the proceeds to work in those that have lagged.
Health is Wealth.