I was using factory-made coils, but just rebuilding gave me a lot more control of my overall end result (vape). I bought one rebuildable, wire, wick, and a couple of tools and went with it. It was surprisingly easy. I watched a couple YouTube videos and just jumped in. The Steam Engine website helped in telling me how many wraps based upon my gauge of wire and internal diameter. Within a couple of four days, I was running fine. Being self-sufficient so I don't have to pay high sales tax on buying coils is also nice.
28 gauge is flimsy and delicate for me, so I use 26 gauge generally. I used a small screwdriver to wrap around at first, but then got a Coilmaster for exactness. Depending on the deck space, I use 2.5mm or 3mm for inner diameter. Plugging these into Steam Engine tells me how many wraps to use. Check out YouTube Videos.
All-in-all, I find it relaxing. It doesn't take long and I think homemade coils last a lot longer than factory coils.