manon_981, you and your partner sound as if you could benefit from a method of teaching the waltz that I learned long after I was an accomplished waltzer. The idea behind it is that, at the beginning, you don't try to teach the steps; rather, you do the minimum steps needed to get the body turning at the correct rate. The feet just about fill themselves in once you get moving quickly. Here's how it goes (I wish I could just demonstrate it -- it's so much easier that way):
Each person will be making his way along a straight line across the floor, separately, to start.
Stand with your right side pointing in the direction you'll be traveling (line of direction, or LOD).
Pivot 1/4 turn to the R as you take a small step (try not to travel) on your R foot in the LOD, then touch the ball of your L foot on the LOD (don't transfer your weight) as you continue turning another 1/4 turn. Your L side is now facing the LOD, you are standing on your R foot, and your L foot is extended in the LOD, ball of the foot touching the floor.
Step onto your L foot and close your R foot in to your L foot, continuing the turn in the same direction so you end up as you began, with your R side facing the LOD and your weight on both feet. Repeat over and over, gradually increasing the tempo until you're up to a moderate waltz tempo.
The timing is:
1 - step R (trying not to travel)
2 - touch L (don't transfer your weight)
3 - hold
4 - step L
5 - close R foot to L (completing 1 full turn)
6 - hold
Eventually, you can step on count 2, but make it a step onto the ball of the L foot, and on count 3, your R heel continues moving around and sort of closes up toward your L foot. If you have to travel more, you can actually take a step on your R foot on 3, bringing it all the way in to the L foot. But if you're waltzing very quickly, you want to keep your steps small, and you don't even need to take a step on 3 -- it's just "step-touch-hold".
You eventually make counts 4-5-6 into 3 steps, but you still want to step down on the L foot on 4 right where it was touching, and your step on the R foot on 5 just closes up to your L foot, mainly just allowing you to continue revolving. The step on count 6 also stays under you, completing the revolution.
So really, you to very little traveling. You mainly travel when your L side is facing the LOD. Then you step basically in place while you complete your revolution so that your partner can travel. That staying in place is essential -- if you keep traveling, your poor partner has to try to travel even more than you, and that's one reason you can end up not making one revolution every 6 counts. (It's actually a little less than one revolution if you're traveling in a circle.)
Of course, one person has to start the sequence the way I've described it, while the other starts it halfway through. It's the follower who does the timing I described above. When you get to the point of having people try this as couples, start with the follower's R side to the LOD, and the leader's L side to the LOD, standing on the R foot with the L foot extended to the L (about to start step 4).
To make it all work more smoothly, the follower needs to give firm support with the R hand in the middle of the follower's back, the follower needs to keep a firm R arm, and both dancers need to feel their weight pulling away from each other slightly. This doesn't mean to lean back; stay upright but let the other person support your weight just slightly. This is necessary to get that feeling of centrifugal force that makes waltzing so much fun.
I know this must seem very complicated, and it's so easy to demonstrate. But give it a try -- I saw it work very well with a roomful of beginners.