[john-aj]

Learning about phonetics absolutely helps. It provides an accurate way of precisely describing how sounds are pronounced.

Do keep in mind, though, that the IPA classifications that you find on Wikipedia are sometimes rough estimates. With particularly difficult sounds, it may be a good idea to look at multiple phonetic descriptions.

Begin with the sounds of your own native language, which you already know how to pronounce, and try to describe them phonetically. A tip for learning to feel where your tongue is, is to pronounce the sounds without tone, i.e. whisper them, or even without air, i.e. simply mouth them.