get a massive peice of newsprint paper and draw big circles and improve your accuracy on those circles use your arm try straight lines across the page too let your shoulder and the pen become intuitive to your being as hit the most perfect bubbly circle anyone has ever seen. BE THE CIRCLE
another technique: draw a random line on the paper and try to turn it into a realistic product or something from life off the top of your head
another advanced technique: if your drawing curved forms that seem too complicated to make out draw straight lines off the outermost point of that curve and the end points of every curve and put every line into perspective.s helps with learning to visualize what your drawing from the inside out and potentially create new shapes in the process too on accident.
another technique: probably the most simple and yet overlooked technique draw what inspires you, if ever your feeling bored of drawing or lazy this is my go to technique for breaking free from it all.