Last month I got full G license in my first attempt, with DriveTest, Guelph, Ontario.
Here are few points for new immigrants who already have driving licenses from their residence countries:
1. Bring the experience letter from your country duly attested. I have Dubai license, so I arranged letter from RTA duly attested by Ministry of Foreign Affairs
2. You need to show your original license too
3. You will have only one chance to pass G license, if failed then go back to G2 test. So be careful
4. In Ontario, G test is not at all easy. Its duration is 30 min but you should know Canadian driving techniques. There are -mostly- no right turning exclusive lanes in GTA/Toronto (whereas in UAE they have separate right-turning lanes, you cant turn to right from signal). Few signals in Toronto have no exclusive left-turning signals, so you have to wait for incoming traffic before turning left. Learn parallel parking, three point turn, emergency/uphill/downhill parking, and lane changing techniques seriously. Follow speed limit sign boards religiously while taking the test. With these differences, be careful while taking G test.
5. It is in your best interest to take 3-4 practice classes before going for G test
6. Driving Instructors, mostly Indians or Pakistanis, are same as they are in their home countries. You know what I mean, so be careful. They will try to make money out of you. An hour long class with driving instructor is costing $25, so manage your instructor with ease.
7. On the day of test, you need a car too. So same instructor will take you to test place in his/her same car but you need to pay extra i.e. around $75-$100 for that day, plus you have to pay G license test fee that is $95. Its all money so be careful while taking test, its costly affair.
8. Full G license cost me around $400 inclusive of 4 classes ( @ $23 per class) from a very good instructor including all fee (G1($85) & G test($95) fees) along with car ($130) on the day of test, as I went to Guelph Test Drive center, some 100Km away from Toronto.
Hope this helps others.