It is very easy to spot LEO satellites during dusk or dawn. I am wondering if satellites further out in a geosynchronous orbit are also visible. Of course, if even possible, these would appear more stationary than any LEO satellites.
No, and the reason is simple enough. GEO is at an altitude of 35,786 kilometres (22,236 mi) above the Earth's equator and no satellites in geostationary or geosynchronous (GSO) orbit are large enough to reflect sufficient amounts of light towards the observer with their truss and solar panels to be visible to the naked eye on the surface of the Earth. They're simply too far away and the atmospheric diffraction doesn't help either, further blurring small and faint objects of high apparent magnitude.
If you're extremely lucky with weather and other conditions from where you're observing (especially the light pollution, described e.g. by Bortle scale, should be as low as possible to detect such faint objects), you might be able to see some with powerful binoculars or a hobbyist-grade telescope, as claimed on e.g. this website. I'd imagine though that it would only be possible from high altitudes where you'd deal with a lot smaller atmospheric effects and shouldn't be much light pollution. Observing them when transiting a brighter object in the background shouldn't help much either, again due to diffraction. If you're incredibly lucky though (just musing with infinitesimally remote chances here), a foreground object in lower orbit or upper atmosphere would momentarily align with a GEO satellite, and you might, might be able to observe slight lensing effect on its body, if the foreground object had magnifying optical properties, say a burst of translucent propellants ejected out of a rocket's nozzle. But what are the chances of that happening?
No, but they are easily seen with a small telescope on a sturdy mount. March and September are the best times. Use an app to help you. My favorite way is to keep M11, the Wild Duck Cluster, in view with a medium power eyepiece. Every few minutes, a "star" will slowly track through the southern edge!