I always pencil in the positions of the brighter field stars, then draw in the object or objects as the case may be. Wide field eyepieces make sketching objects a lot easier, especially since many of the objects I observe are tiny and require high magnification to distinguish them from the surrounding stars. An equatorial platform might be the way to go for you as well, because any equatorial mount that could handle a 12-inch solid-tube Newtonian would cost much more than $2,000 and would be a major hassle to transport and set up.

Taras