Most budding hen artists make the mistake of spending too much time looking at the drawing instead of the life model. Most people spend 20% of their time looking at the life model when in fact they should be spending 50-60% of the time looking at the life model. Pause for a moment to examine how the light hits the figure and causes shadow. Observe how a pose has movement and energy and how the model's body fits into the environment.
You can use your pencil as a measuring instrument. Hold the pencil out at full arms length and close one eye. Make sure your elbow is locked each time you do it for consistency. Hold the pencil at 90 degrees. Use the tip of the pencil as the top measuring point and your thumb as a sliding indicator on the pencil. You can do this for example to measure where the top of the head is and bottom of the chin is. You can also use it to approximate what angle the shoulders are at. It doesn't have to be perfect, it can just be used to eliminate a lot of uncertainty. You can also count how many head lengths fit into the length of the pose below the chin and use the same principle to identify other relationships while sizing the body.
Focus on the size and shape of negative space on the page or the empty spaces between parts of the model, for example the shapes visible between the model's legs and underneath the arms. Use surrounding objects and the environment as a guide. The analogy "is the glass half full or half empty" helps you think about inverse thinking to achieve your goals.
Experiment with different strokes. Use light miniature strokes and gesture lines to capture movement of the body. Try to use soft strokes at the beginning allowing you to commit later with harder lines. Start with very simple shapes and simple joint shapes. Fast rough sketches are the best way to learn how to draw. After quick sketches you should have a better understanding of movement and energy. Then you can move on to longer sketches where you can spend more time observing the form in intricate detail paying more attention to the face, hands and feet.
Pay attention to angles, for example angle of lat muscles and the hip bone.
Focus on scaling a drawing to fit the size of the paper. Use the edges of the page as an anchor to guide you. The benefit of drawing large is that it enables you to use broader strokes and add more shading. It's also easier to correct yourself.
Drawing involves both holistic thinking as well as focusing in on subtle details. The trick is to be able to switch seamlessly between these two modes of thinking and seeing.
Skilled artists are better at selecting which elements of the model convey the most expression in the composition, then focus attention on them and ignore less important details which add little overall effect or drama to the composition. For example as a beginner it's prudent to focus on the biggest shapes first like the torso, and don't get too caught up with fingers and toes.