When you want to describe how something is completed through a sequence of steps, you use some transitional signals. Here are examples of transitional signals:
Firstly, Then, Finally,
Secondly, Next, etc.
Thirdly, After that,
First of all, Later,
Besides using the transitional signals, you can also use the imperative form to give instructions. Look at the example.
Log in to Yahoo home page.
Click the 'Sign Up Now' link.
Click the 'Submit' button once you've finished making changes with Site builder.
Enter the 'Verification Key,' which is the letters and numbers that appear in the displayed image.