Emphasis is good, but if you don't like it, then the word you are looking for might be stress. I would say "Stress the last syllable" which is almost the same as emphasising the last few words.

When you say "pronounce more", what do you mean? Do you mean louder, and dwelling on the vowel, possibly at a higher pitch? That would be stress, as other commenters have remarked, and it would apply to the whole of the syllable, for example, as in "repreSENT". But you are asking about consonants, and S, T and D in particular. You might also find them in unstressed syllables, such as in "[a] PREsent". It can be particularly difficult to hear those consonants separately if other similar consonants occur in combination in the flow of a sentence, such as in "presents sent directly" (on each word boundary). So I wonder if you mean "pronounce more distinctly", for which there is the word "enunciate".

"Enunciate" fits better than "emphasise" and "stress" I think. E.g. "I need to enunciate consonants at the ends of syllables better".

Stress or accentuate perhaps?