Attaching Decor to terrarium?

[deranged chipmunk]

You can glue earth magnets to them and use another on the outside. I would only use earth magnets though, due to their unequaled power.

[maxQ]

I use tiny or medium size suction cups, I use tiny plastic wire ties (zip strips) to attach whatever is to the suction cup. You can also buy suction cups with loops attached to them at PETCO or online for attaching decore and plants to glass, they work well for me.