Patent drafting is a group exercise which should be prepared by 

1. the inventor
2. a patent specialist (expert/lawyer) 
3. A person technically experienced in the field

Collaborating while drafting a patent assists inventors in drafting strong applications and ensuring the three main criteria for patentability are met namely - Novelty, usefulness and non-obviousness. There are many assistive tools for patent drafting on a do it yourself basis, but technical expertise from patent lawyers and experts should not be undermined because a well drafted patent is half the battle to obtain protection. 

Patent filing is the process of depositing a patent application at the respective patent office. Where a patent is filed depends on where the inventor would like to protect the patent. Upon filing, an inventor receives a filing number and filing date, which are both key numbers used and referred to show patent protection start date.