Eliminate the need for your ball to have sidespin by strating it at the target line and keeping it straight, which also helps increase the backspin
If you have a fast tempo and swing Tom Watson is the perfect model, he was quick through the entire swing but made a few adjustments to compensate for his speed
Many faults in a bad putting stroke are the direct result of poor aim which causes manipulation in the swing to square the stroke, fitting your putter properly can help fix your aim which will fix your stroke naturally