What is your age, and are your knees healthy?
Only asking because the only answer I can think of would be to go back to the basics of Latin motion and just work on that in a stationary position.
The rumba steps in the American style are generally very small, so sometimes you have a near-stationary look in the sequences.
I am older, so I most definitely do not have the "twist" as you refer to it, in my hips that I had some 30 years ago. Other posters will weigh in on this, but I actually don't prefer to use the term "twist" for beginners because it makes them think it is an actual "twisting" motion that has to be initiated above the belt. In reality, regular Latin motion with the legs and knees doing what they are supposed to do should suffice in the majority or rumba steps, and your hips will "twist" rather naturally.
Go to the Latin motion learning portion on this site. Very basic, but very important. And your knees have to be healthy.

If she is speaking of Latin though...the term twist is used in the name of some basic steps and not really as a descriptor.

Closed Hip Twist...followed later on by Open Hip Twist...etc.

Ahhh .... could be what emma meant, though it wasn't entirely clear. I suspect you are correct, though.
I was not as familiar with the names of some of the advanced International Style rumba steps. Thanks for clarifying. American style is the only rumba I have learned. That is sometimes a tricky part of this message board. Posters start sharing their knowledge or thoughts on something, and in some cases it is an entirely different dance from the original question.
Either way, we have it covered -- if emma is more advanced, your post helps tremendously. If it turns out she's just starting, then maybe my thoughts would help.

dhuen,

I am completely in agreement with you.

I would definitely say, as previous posts argue that you need to work on your balance as this is important in the Rumba. Try strengthening your balance and working on your core and upper body balance to generate a graceful and elegant movement. Once you have the upper body sorted and your balance sorted you can then begin to work on your lower half and feet movement and hips etc.

Basically to cut a long story short, work on your core balance first and then try adding the feet until you do not wobble. You must be able to do it yourself without help. Do not rely on a teacher or partner to get you through it!

Practice makes perfect!

All the best :)

Practice makes perfect ?

That depends on WHAT you practice .

The 3 things that ALL dancers need to perfect are..

1.. Muscular control

2.. Timing control

3 .. Balance control

As Irvine said.. lose anyone, and you lose all 3

I agree, it does depend on what you practice!

On the Basic Rumba I was told to imagine that in my belt about 4 Inches each side of my navel are two pencils. If I imagine that I am trying to draw a figure eight , the infintity sign. Starting to my left anti-clockwise.
What I should remember is to rotate around my own centre and not move my centre either to the right or to the left. There is the Movement of the Hips

Another nice trick which I teach a lot of my students is to imagine I have given you 10 1 coins and you put 5 into each trouser pocket. I ask them to walk without making any sound from the coins in their pockets and before they know it they are doing the rumba :)

Try it!

I've always liked the visual "tricks" when explaining something to a beginner as well. These are good ones that were posted. I had seen the figure eight reference, I believe, in a Maksim Cherkovskiy video. Of course, he makes it look so easy it's ridiculous. But the pencils idea is a great reference visual when teaching that hip movement. I will have to slip some coins into my pocket -- if I can find some coins -- to try quickstep7's interesting idea.