I use traditional manufacturing techniques as far as possible: my main forging tools are the charcoal-fuelled forge (charcoal being a renewable energy source) and the handheld hammer.
My workshops do not contain a power hammer of any description: I use human-power only. Just occasionally I will use a gas forge for some of the "cooking" processes that I use, such as some modern pieces, and others which are not carbon specific in their end use. The modern angle-grinder, power file, etc, have their place in greatly reducing man-hours (by comparison with the old-fashioned file) but a lot of pieces are still hand-finished with a file for a more accurate fit.
This does not mean I ignore modern developments. I also work on modern designs, taking my influences from much older technologies. So you may find me using a CAD drawing system, a laser cutter or modern stainless steels (amongst other materials) as part of my finished design.
However, if I'm asked to produce an historical piece, I try to reproduce the item through faithful adherence to materials and working techniques, as well as the overall look and finish. These methods infuse something of the history into the artefact, giving a more realistic feel and performance to the finished article. I am aware that the originals of many of the pieces I produce are highly collectable, and while using authentic materials and production method it becomes difficult even for experts to differentiate between an original and a good reproduction. This is why I always change the original designs slightly, and/or mark the pieces with one of my "logos".