The males may follow the female, giving occasional nips to the tail, till they finally secure a firm neck hold and attempt to mate. If the female cooperates by raising her tail, the breeding event is going very well. Males can be very aggressive, so anticipate bite marks on your females. Don't leave them unattended. Breed females several times over the course of a month or two for best results.
Gravid females eat voraciously until they are near full term.
Gravid females may get very aggressive - but be happy, the babies will be born in about 4 months. The Germans have bred blue tongues for generations, and this book gives detailed husbandry and breeding information. Best field guide to Australian herps, but little captive maintenance information. The Vivarium, American Federation of Herpetoculturists. Most comprehensive articles on lizard husbandry, and well worth a subscription.