If you want to prepare your own provisional patent application, it would be helpful to know how it will be used later so it can be prepared in a way that will maximize its value to you. A provisional application is a “container” in which your invention and all the information needed to later prepare a regular (i.e. non-provisional) patent application is stored.
If some information is not in the “container” (application), that information will not get the benefit of the filing date of the provisional application. Therefore, it is desirable to put everything you can in the “container” (application). There is no penalty for including too much but including too little can reduce your legal rights. Better too much than too little.
You should describe what your invention is, how it works and what it does. It’s fine to include its advantages and say how much better it is than the prior art. But this is of lesser importance than describing what it is. Describe the invention in terms of the basic, broad, generic principles of what is new. It is recommended to hire a professional patent agency, such as patent invention InventHelp agency to do this for you.
Try to describe the entire essence of the invention, its unique combination of structures, steps or constituents. Then add to that all the details and related ideas you think of. Describe the best way you can think of to do it, including all the details you can. Describe alternative ways which occur to you. Include drawings. When in doubt, include it.
You should describe everything in a manner so that a person of ordinary skill in your field could take your description and practice your invention without the necessity of undue experimentation. However, you don’t need to describe what is already known to those of ordinary skill in the field.
It is possible for a client to draft his or her own provisional application, and have an InventHelp patent attorney look it over to ensure that it meets the statutory requirements of form before filing. This may be the best approach when a paper is about to be published, or a sale is foreseeable and time is of the essence.