What do you want to do to the camera JPGs, which you already like? RT can probably do some, maybe all, of those changes. Open the JPG in RT, but save TIF files while you work in order to maintain highest possible image quality.
Or you can try to find a recipe that you can apply to raw files. You can read the white balance in the Exif of the JPG and set RT to the same temperature and tint. The exposure slider, the Lab-L curve, and the Lab brightness slider are tools for you to try to match the contrast of the JPG. As already noted, camera JPG colors are put through an unpublished set of changes to get the Olympus look, the Fuji look, the Canon look, etc. Some of the color tools you can use to go from a raw file to an approximation of the JPG are the Channel Mixer and the HSV Equalizer. Compare a JPG color with what you have from the raw and ask yourself questions like, did Olympus add more red to orange? If you achieve your goal, save those settings in a partial .pp3 file and use it on future raw files.