This came from my local jeweler who funnels most of their non-routine engraving jobs to me. Often, items require hand-engraving that typical store machines cannot handle.
First, if the item is a watch, I make sure the customer or jeweler knows that unless the band is leather and can be unbuckled and laid flat, the bracelet-type band MUST be removed on each side of the watch. The only way I can get a comfortable hand position on the back is for the band to be gone as shown below. If I need a circle template for a circular baseline, the band on most watches will be in the way.
To be sure I had the right bur to get the complete message engraved in the available space on the watch, I found an empty stainless steel flask. I placed the template on the back of the watch and drew the circle that would give me the maximum space. There were small imprints outside the circle that I had to consider for the letters with descenders.
I then drew the same circle on the flask, picked a #1 round carbide bur and engraved the message. Ran out of room. Drew the circle again and got a bur one size smaller, a #.5 round carbide. The second time the message fit, so I went to work on the watch and, though a tight fit, it worked exactly right.
In the photo above you see the comparison in size with a #4 round on the right of the .5 round bur I used.
This would have been about a $145. job for a customer bringing it to me; I had to engrave the 10 words 2 times, testing to get it right, before the final engraving on the piece. In this case, in my arrangement with the jeweler, no money changed hands. Here's the way it works.
The store sends me customers and phone inquiries almost daily. Around holidays, I often get 4-5 a day. Some regular customers of the jeweler are handled by their own limited engraving facilities at the store. Other regulars don't want to be passed off to a third party so the store brings the items to me and I engrave per their instructions.
The arrangement works wonderfully for both of us. They send me tons of referrals and I pay them no fees whatsoever. On the other hand, when they need work for their regulars, which they often do, I do the work and they pay me nothing; they charge their customer for the engraving at whatever they feel is appropriate.
I highly recommend that approach for you and your customers. If you're dealing with high-end luxury items, the system would definitely need some tweaking. That's a negotiable thing with you and the jeweler.
Oh yes, the customer paid nothing to the jeweler for this watch engraving. The watch was purchased at their store by a military man, so this was the store's 'thanks for your service.' That made me even prouder to have been a part of the project.
Go make friends with an area jeweler or two where you are. It can be a steady source of income when you're ready to handle what they may bring or send to you.