The design and commissioning process can vary from job to job.
However I can give you some general guidelines to help you understand what is involved.

• ​initial discussion by email, or phone call
• site visit or email with preliminary sketches and costings
• site visit to discuss and agree final direction and specification for work
• final drawings and final price for job
• payment of deposit
• manufacture of work
• delivery and fitting
• final payment upon completion

I would normally ask for a 50% deposit of the total job cost before starting. This is to cover material costs and initial labour costs.
​With the final balance paid upon completion.