Improving your pivots in tango makes a lot of moves easier. Ochos, turns, boleos, . . . the list goes on and on. Pivots are just as important for leading tango, but I have been focusing on making videos for followers to improve their own dance. It seems to me that many classes only focus on how to lead tango, leaving the followers to do the best they can with little information.
Build your body map
If you spend some time working just on the pivots, your moves will improve. Finding what muscles work in your body to make a good pivot, helps you build your own "body map" of how the body works. Then, if something is not working, YOU can detect and fix the problems. Having a good teacher is very important, but that person cannot follow your around the dance floor, pointing out when you have successfully done a move, or when you have made a mistake.
Take the time to work SLOWLY on your pivots. Feel how they work in your body. Focus on your feet, or your hips, or your abs, or whatever part you are working on. Once you have a good feel for that part, add it into your body map until you can see/feel how all the parts work together. For me, when it is working, I feel as if there is a fiber optic cable running through the focus points, lit up like a Christmas tree. When something is not working, one of those connect-the-dot spots fails to light up.
After many years of working on my body map, I can tune into it pretty easily, but it took a lot of work to get to this spot. Don't give up!