Learning Spanish from many different sources it is easy to lose a traditional Puerto Rican accent. Here is me attempting to understand and explain aspects of it. This will be a big work in progress as I gather more input from different people. Mostly this will be from my parents, who are from Rio Piedras and Carolina.
Accent changes depending on where in the island you are. There are some accent things that are most associated with jibaros, or people from the country.
The best way to learn this stuff is to talk to Spanish speakers and have them give pointers on your accents. Don't force any of this without knowing what you're going for, as a lot of this is hard for me to explain in text.
S's will sometimes get lost. "Los que dicen" can sound more like "Loj que dicen" or "Lo' que dicen." "Es que" can sound like "E' que" or "Ej que."
Used the same as "Um..." Often said "E'te" or "Ejte".
A lot of times words that had an "ado", like "Enamorado", will get the D dropped. "Enamorao". It's similar to dropping the g at the end of the words in english, "Running" to "Runnin'."
You can hear this very clearly in the song "El Dilema" by La R. In their song "No Hay Que Ser Bonito", there's a line that says "Meñiando sus caderas de lao a lao... tener abdominales y estar bien cortao!" Here, "lao a lao" instead of "lado a lado," and "cortao" instead of "cortado."
You can also hear this in the game briscas. The words "envidado" (meaning you have a lot of life cards) and "embriscado" (meaning you have a lot of briscas) are always said "envidao" and "embriscao".