There are different methods to estimate terminal value in a DCF valuation. You can estimate terminal value in a DCF valuation using any of the common methods: perpetual growth rate, a multiples of earnings, cash flows or revenues or less common methods such as orderly liquidation value; or a fire sale value.
The method you chose depends on the stage the company and expected growth drivers as well as the information available.
For example, if you have a reasonable estimate of terminal growth, the perpetual growth rate method may be good. If you do not have a reasonable estimate of terminal growth but have good comparable companies that are traded in the market, then multiples of earnings may be a good choice.