The breeding season is over for them in most parts of the country. The Notopthalmus sp. found in warmer climates (Southeast) seem to breed easily with the room temperature drop of 10-12degrees (F) and the normal change in light cycle. If your newts are from a colder climate, they may need temperatures that are refridge range. Sometimes garages in the wintertime that is unheated stays in the 40-50F range (depends on your location).
After a cooling period, place them in a well planted tank with lots of live food (black worms and even zoo plankton) and simulate springtime. The temps only need to be in the high 50F. They should start showing their breeding characteristics. They do lock together with their hind feet and the males have a noticeable caudle fin with pronounced cloaca. Females are very plump and round. Try different plants and have lots on board to remove the egg infested ones with fresh (elodea and eel grass works well)
Got to warn you though, efts are very pretty to look at, but can be difficult to rear in large quantities. The first several months after metamorphosis was always a challenge for me with feeding land based microfoods (fruit flies/pinheads)
good luck
Al