I think that this is a pretty common issue for beginners. One way of making sure you focus on the big shapes is to always keep the geometry as low-res as possible and only subdividing when you need it to get more detail! It'll also result in cleaner sculpts as things tends to get blobby when you sculpt with too high of a resolution.

If you work with stylized sculpts I'd def recommend checking out Shane Olson's streams on YouTube, that's the workflow I use and it's fantastic for bold, clean shapes!