If you remember that these - está, están, estás - are exceptions, than you remember the rule.

Words with all the other endings have an accent on the last syllabus.

Question and exclamation words - comó, dónde, qué - always have accents.

Demonstrative pronouns have an accent as opposed to demonstrative adjectives.
éste -- este libro, éstas -- estas blusas

Certain words change their meaning when written with an accent.

cómo how como like
dé give de of, from
él he/him el the
más more mas but
mí me mi my
sé I know se 3rd person pronoun
sí yes si if
sólo only solo alone
té tea te you
tú you tu your

Referring to females and/or ending in -a -ción -tad -dad mujer, mesa, nación, libertad, universidad

Ones referring neither to males or females
and having different endings can be of either gender el lápiz, la clase, la tarde, la noche

Many nouns change gender by changing the last vowel or by adding -a to the last consonant el compañero, la compañera, un profesor, la profesora

Many nouns have the same form and differ only by the article el estudiante, la estudiante

Some nouns ending in -e change gender by changing it to -a el presidente, la presidenta

Remberber: El día and El problema are MASCULINE.

Many words ending in -ma are MASCULINE el problema, el sistema, el programa

ending in consonant consonant + es un papel
la universidad unos papeles
las universidades

ending in consonant z z -> ces el lapiz los lapices
to refer to a group consisting of both
males and females masculine plural is used . el amigo
la amiga los amigos

As you see, two vowels -- e and i -- are exceptional.
To remember them, remember two words -- que and quien.