How to describe a sequence of actions?

Hi, Dear sir or madam:

Could you please explain how to describe a sequence of actions in English when communicating with other people?
For example, below is a guide of how to send eamil using Express.
First, click the Express icon on your desktop, then the express starts up. then click on the 'Composing ' button, then a window with a blank text box displays. ......

If it is a long sequence, lots of 'then' would be in the paragraphs. It is not good, right? and what tense should be used in this senario.


thanks

[Tdol]

Next, after that, having opened..., secondly, thirdly, lastly, etc.