Doing Tango means constant practice. You need to attend classes, take privates, attend practicas and milongas. If you do not, you become rusted very soon. And what is worse, your partner can tell and feel the difference.
Generally people ask, "How long have you been dancing for?" Referring to- how many years.
According to me, the apt question should be, how many hours of practice have you put in your dance. There are people, who claim to be dancing for 15 years and can barely walk well. Whereas, there are others, who have put in 5 years and have exceeded them. The difference is the numbers of hours each day the later has put in their practice, the number of lessons taken from the maestros, the number of festivals attended, the amount you have invested in your dance.
From the moment of my first embrace, I can clearly differentiate between a good leader and an average one. Before he takes his first step, I can tell whether he is a beginner or advanced. Then I know whether I need to work extra hard even for him or can he take care of himself.
Same goes for the leaders. They can tell, if the follower is advanced or beginner. Has she been practicing her pivots, or is she rusted? The first embrace tells it all.
I may neglect to eat food, but I can never miss my daily practice- with or without a partner. That is why, in cities, where Tango is booming, people have the opportunity to attend milongas 7 days a week. And they do attend them. If you do so, you are an altogether different persona on the milonga floor. Everyone notices and you get the best dances.