9 steps to create Technical Documentation

1. Read the Marketing Requirements Document (MRD) and functional specification. The MRD should list out clearly the documentation requirements.
2. On the basis of MRD and functional specs, create a documentation plan that includes
•  Product name, scope, and purpose
• Milestone dates 
• List of documents that will be created and/or updated. If the project is about updating an existing product, list the features to be documented. If the project is about releasing a new product, additional planning is required. There are multiple customer documentation deliverable types a project could require, ranging from a single-paged addendum to a context-sensitive online help system.  
• Features that will be documented
• Work estimate and committed schedule for documenting each feature or completing each document 
• Committed documentation milestones
• Documentation Reviewers including review schedule. There are 2 ways to conduct a review, collect edits individually from each reviewer or hold a review meeting to review everyone's comments. Multiple reviews may be required. You can also use Adobe's Shared review process to collect feedbacks from multiple reviewers.
• Depending on the program, include any training material needed for the Launch.
• Risks, assumptions, and dependencies. Include the following: Main risks of the documentation project (e.g. last minute feature additions), probability of each risk, Impact of each risk, Risk mitigation plan, Owner of the mitigation plan)
• Affected BOMs and/or document numbers
•  Doc approval process and approvers (outside the tech pubs team)
• Documentation delivery and distribution plan.
Distribute the plan to the core team members: PLM (Marketing), R&D lead (Engineering),  and PM (Program Manager) who will review and approve the plan.
After the approval, create the draft document by attending the core team meetings, interacting with the application, studying design documents, asking questions to the testers/developers.
Send the draft to the reviewers identified in the documentation plan.
Update the documents as per the review comments, address all the major and critical documentation CRs and defects identified during the documentation validation.
Obtain the documentation approval from the designated reviewers/approvers.
Generate the final version.
Check in the final document into the build branch.