EDIT: You DON'T need to collect the final move on every routine. This move turns gold when you get every move in that routine.
If you played any previous Dance Central, this is not so difficult. If you played every Dance Central and get every achievement, better.
I have every DC complete, I'm not a expert dancer, so only with patience and practice I collected every move.
First, play in the same language that you played others DC (I speak spanish, but my 360 is in english, so I know moves' names in english). Knowing the name of a movement can give you a better idea of how is it.
For practice mode, you don't need to say "Hey DJ, Practice That" (or this command in other languages), just press Y in the controller. This help because Kinect doesn't always hear you if you have loud music
DCS is almost 80-85% previous DC moves.
Remember that you can slow a movement in practice mode. Sometimes in slow mode I get flawless, and when I speed it up, I failed to get flawless, and vice versa. So I used Slow mode when I didn't understand a movement, to see if start with right or leg arm/leg or something like that.
Kinect sensor is more accurate, so if you played others DC, you maybe don't get flawless in movements that you do flawless, you need to "know" the feeling of this new kinect. Even so, I practice a move like 30 times, I get flawless in practice and in the song, and while I was waiting for the next not completed move, I just do a "lazy" version of the move that I practice 30 times, and get flawless. So if you can't get flawless on a move, try a more lazy or exagerate version. (This is random, I only post it like a little "glitch", maybe you can get 10 moves "lazy" or exagerated, or 3, or 0 )
If you can't get flawless on a move, and you are tired, or you HATE that move, take a break. If you still don't get it, search in Youtube for videos, look carefully the "shadow", and if you really can't do it, call a friend/family that can see you dance and can compare your moves with the character. Sometimes is leaning forward, backwards, some extra step that you can't see, etc.
If you want to try it, go for the most easy songs (and play first the normal routine, and when you get every move, go for alternate). DCS don't have sort by difficulty, so I sorted from easy to hard (IMO)
Wake Me Up
Counting Stars took me almost 3 weeks. I remember that I have problem with Piano (both sides) and Triple Pump (right side) and more moves, but I don't remember. Maybe you don't have problem with this song, maybe you get stuck, or maybe you find that Wake Me Up or Titanium are more difficult.
Good luck with this ;) and don't hate the song if you can't get a move. If you don't like a song, leave it for last.