Why create one? _ "Re_inventing the wheel", is no fun. If you work for a single organisation it's likely that your templates could last a long, long time with no need to go back to the design board every time you are asked to create a new manual or user guide. When you work for yourself it's a great way to show clients that you have the skills they are looking for without breaking any confidentiality clauses with your existing clients, and with just a little bit of luck they'll adopt your method of working so you can continue to recycle your past efforts too.
Whether you are a technical writer working for a single firm or a freelance writer working for many companies, you can benefit from creating templates for your documents. In the long run a good outline will save you time and effort, and deliver that elusive consistency to your material that users will appreciate. Here's how you go about it.