Completing the drawings

I've developed a way of working with my technical drawings, where I only draw a section (i.e. 1/2, 1/4, 1/8) and then I scan in the drawing and complete it using Adobe Photoshop to ensure that my drawing is then accurate and easily repeatable. The pieces of jewellery that I am making studies of are very symmetrical and detailed, something that would take me quite a long time to complete by hand - especially as I like to include lots of smaller elements with my fine liners. This was relatively simple for the first few of my drawings, it was easy to just duplicate the original layer, mirror and rotate, then merge and repeat these steps until the shape was complete.

The below drawing is one where I started to encounter some trouble when trying to repeat the designs below, they had a more complex pattern that meant mirroring wouldn't have given me the look that I was aiming for. This design (below) wasn't as much of an issue, although I had wished for it to go under, over, under, over as it went around the circle, I don't think it is noticeable within the pattern that this was my intention. It still flows rather well and is interesting on the eye, when trying to follow the track. 

However, when I moved on to completing this drawing, mirroring definitely wouldn't have worked for me. For starters, I let myself down in the beginning stages of the drawing when I wrongly calculated the angles in the centre of the design, which then informed the rest of the piece - ergo, it's all wrong. No fear, I'm smarter than I look... Hopefully. I began by taking the half circle that I filled in with detail and made this into a full shape. After then duplicating this twice, I rotated the new circles 120° around the central point of the inner circle, creating a equilateral triangle in the centre, meaning all the circles are now spread evenly around the 360° centre. I then used the magic wand tool to select one circle layer, then keeping this selection, I worked on another layer to erase only the part that would go under the selected circle - finishing with a more complex and more accurate under-over pattern than before! Challenge complete.

As I created more drawings, my system started to develop and helps me quicken my pace. By realising that I need to draw even less that 1/4 or even an 1/8 of each piece meant that I didn't waste time with repetition - I just drew a few details and then repeated those to fill a fraction of the drawing that was repeatable, and then worked as I would from there. To begin with this took me a little time to get used to, working in more detail in Photoshop was time consuming but I managed it eventually. I'm going to continue this as a build a bigger library of drawings for the coming project.