A good rule of thumb is to take your age minus 10 percent and allocate that percent to intermediate bond such as the Vanguard Total Bond Market Index Fund. The balance invest in a diversified stock portfolio such as Vanguard Total Stock Market Index Portfolio. With full employment and the economy growing rapidly, inflation should be a significant concern. If there is more demand than there are goods made, then inflation is likely to increase. If there is more demand for labor than there are workers, then wages, costs, and therefore prices are likely to increase.
Productivity is key.
If the worker stays productive, then the economy and real wages can continue to grow at a reasonable rate without inflationary pressures. Many newspapers give a letter grade based on how well a bond fund does compared to its appropriate peers. This is a good start. What you will find is the cost is key. Thanks for the question.