In (mostly) mathematical publications, when proving a theorem that can be generalized to a wider range of parameters, is it generally considered better practice to:

- Present a special case of a theorem first, and then prove it in a general context, or
- Prove the general case and then move on to present one (or more) special cases?

The first approach makes understanding the theorem easier, and makes the paper quicker to read. The second one looks more “rigorous”, but is much more difficult to understand for more complex theorems and formulae.

What is generally considered the better practice?