lapdance, there has been mention of a range and practice green possibly coming to WGT in the future. As for now, like mentioned, do practice rounds and use the 10 shot limit, obviously a par 3 will give you 1 more chance then a par 4 will. But why just practice putting, practice your approach shots just the same, learn where to land the ball and try different spins. The best way to improve your putting is to leave yourself 5ft putts, not 50ft putts.
On another note, I will take a pass on the mulligan option. Its not needed. Not everyone can be the best, there are only a handful of people that can go low almost all the time ( I am not one of them), but they do it by practice. It can be done, by everyone, practice and think.