vivlee

Ooh, for imaging, I'll usually have it in pretty deep water/liquid in my tray, then I'll either try to get both (gloved) hands under the edges to lift it out all at once or I'll tease up an edge with some filter forceps, then lift it enough with one hand to get the other hand under it.  That way the force of moving it is more distributed and less likely to tear.  I wet my gloves before handling gels to help prevent sticking (you should be able to easily slide your finger over the gel without it grabbing).

As for on the imager, I'll usually coat the surface with water first, then set the gel in that one edge first, then easing it down to prevent bubbles.

For getting your gel off the plates, you could also try holding the plate over your container, then teasing a little piece of edge away, then doing the water bottle trick.

One thing you could try is using a water squirt bottle to soak the gel while it's on one of the plates until an edge lifts up, then trying to use the water stream to kind of wedge the gel into your container for imaging.  Or just put the whole plate in with your gel, which might soften up how strongly the gel sticks to your plate, then gently teasing the gel off with a spatula/forceps after incubating/rocking for a bit.

I'm assuming you're using your own gels on glass plates?