I am a huge believer in daily drills. You don't have to take a long time each day, but if you can set aside 15-30 minutes a day to do the same basic thing over and over again, and you focus on studying what you did right and what you did wrong every day, you will see dramatic improvement pretty quickly.
Starting on January 1st, I've tried to do 20 gesture drawings a day, every day. I've missed a couple of days, but I've been pretty good about it.
The more of these I've done, the more comfortable I've become. They are all very quick, very small drawings, but the point isn't detail, it's to abstract and capture the motion and the feel of the pose....and I'm getting way better at at it.
None of these take a long time. If I focus, I can easily do 20 gestures in 15 minutes. We can all find 15 minutes a day to work on improving something that matters to us. I really think 15 minutes every day is better than 2 hours once a week.
Give it a try, I'd love to hear if you think it has helped you!