As a designer, I also used to struggle with the pen tool. Until I learned to plot anchor points on the outermost extremum in 90 degree increments. Let me explain. Take this O for example. In Adobe Illustrator, instead of plotting points here, making it hard to adjust one section of the curve without affecting another, plot points here on the outermost extremum. And adjust point handles holding shift on your keyboard allowing for curve adjustments that don’t affect the rest of the shape. The more complex the artwork, the more useful this gets. Plotting points this way makes it faster and easier to nail the right shape no matter what it is.