I'll just add that we use "rin" after words that end with vowels (A,E,I,O,U) and after W and Y.

Example:

Dilaw rin ang pantalon ko.

However, if a word ends with RA, RE, RI, RO, RU, RAW, and RAY we don't change the D to R.

Example:

Anong araw daw pupunta si Mark sa Pilipinas?

"Bawal magtapon ng basura dito."

You are right about that. You should use "rin" after a word which ends in a vowel and for the "din", after a word which ends in a consonant.

Well to tell you the truth, even though I'm a Tagalog native speaker, I also mixed those two words from time to time so you don't have to worry about that much. I'm pretty sure almost no one will notice it.