You can use the metronome in an aux track to record 3 clicks in a separate audio track. This region thus created can be given as a cue to your artist/talent to dub his lines. And punch in after the clicks to record his lines.
In India we do ADR most of the time but differently. Adr could be for films and even content localisation-translating and dubbing NGC, Discovery, Disney, etc. channels in numerous local languages and Indian content into English for international audiences.
We don't use beeps or tones. Our artists/talents just mark their lines according to previous character's guide track or video timecode on screen. Even if they miss the opening syllable, they continue their lines with the same speed till the end of the line. Since they start about 2-3 frames late, they finish late too. Then we just nudge the region left by the same no. of frames and achieve synch. If not, the talent is requested to speak slower or faster and pause on certain words to match the guide track.