Tuning the trigger/bolt spring is not all that difficult. First, file a slight taper to each of the legs, working the outside only, tapering slightly, no more than a quarter of the legs width. You can grind this instead, but overheating the spring is real easy to do, so it's best to just file it. After that is done, sand then polish the outer sides that you just filed and the inner sides that face each other. The roughness on these edges from where the metal was stamped out is what causes most breaks. The imperfections are stress risers. The hardest part here is to get the area in between, and especially the radius at the bottom. Start with a file if really rough, with about 220 grit if not bad, progressing on up to at least 600 grit, or even 800 grit. The smoother, the better. If you want, go all out and get the 1500 grit, which will make the edges a mirror. Of course, deburr the filed sides first. Then the bending as necessary. Always remember when bending a flat spring to not bend it sharply, but bend it over an arc. Hold it at each end and just flex bend it, going a little at a time. It is better to have to bend it several times, a little more each time, than to go too far and bend it back. You want the bolt leg to push the bolt up with about 2-3 pounds of force, and the trigger with about 1- 1 1/2 pounds of force. This is checked with a trigger pull gauge with the spring installed with the tapered ends centered in the frame, so that the sides do not drag as they are flexed. To check the bolt tension, the bolt is installed and the spring, and using a flat thin piece of metal on top of the bolt, pull down the gauge, pressing down the bolt and reading the tension required. The trigger is checked by simply pulling back against the spring without the hammer installed. The weight of the trigger pull is adjusted by hammer/trigger engagement.
Tuning the hammer spring is the same, except that you can taper it more, and it being larger, it is usually easier to grind it, then finish it with files and emery. When grinding, dip it in water after each pass, don't go slow with a lot of pressure, use lighter multiple passes, and hold it in your bare hands. If it's getting too hot, you'll notice more quickly. Generally, you can take the top end to just outside the hammer roller groove tapering out slowly to the bottom. Use a rattail file at the point where the spring loses contact with the trigger guard near the screw and cut a round groove in either side, then grind down to the bottom of your groove. You don't want a sharp corner. However, I generally don't do this to cap-and-ball revolvers due to the cap ignition requiring more tension to reliably fire than the later design cartridge guns, such as the '73.