I am trying to learn how to palatalize the consonants. As far as I understand, one must bring the tongue closer to the position of where the vowel [i] is produced while still performing the consonant. I read that the middle of the tongue must be positioned closer to the hard palate. As I only have control over the 3D position of my entire tongue and if it is curled or flat, I assume that means to leave the tongue flat, bring the tip of the tongue up and put it close to the teeth (alveolar ridge). As a consequence, the middle of the tongue will be close to the hard palate.
However, plosive consonants (eg [b], [p], [t], [d], [k], [g]) are only heard when they are released and they are released together with the following vowel (if there is one) in all languages I know. So, I cannot understand the difference between, for instance, [bʲa] and [bia]. Could someone clarify?