When making a presentation or writing a essay, I often use words such as "First,...Second,...Third,...Finally,..." .
Could you tell me better words to paragraph sentences?
You can take a more prose like approach:
To start off...
In the end..
If you wanted to be more formal you could use
Firstly, secondly, thirdly,... finally.
which I use regardless of formality.
Since you seem to want to enumerate your paragraphs, you might use
In the first case, ...
In the second case, ...
In the third case, ... Finally, ...