In English, you probably only use the words "masculine" and "feminine" when talking about people, animals and plants.

In Spanish, all nouns have been given a gender. 

Remember that a noun is a 
            person         e.g., Sarah, friend, teacher
            place            e.g., school, Paris, your room
            thing, or        e.g., phone, shoe, bus
            idea.             e.g., liberty, justice, peace

Does that mean that Spanish speakers have tried to divide the whole world into more masculine stuff and more feminine stuff?  No way. 

It's just a simple tool to organize the language.

Masculine words will often end in the letter -o, and will use a masculine "the" - el.
Feminine words will often end in the letter -a, and will use the feminine "the" la.

The cat is fat.
Masculine: El gato es gordo.
Feminine: La gata es gorda.

I suggest that you don't look for cultural clues in the gender of words. You won't find them. 
Dress is a masculine word, and necktie is a feminine word, for example.

1. Nouns that end in -e only have one form and can be either gender. If it's a person, 
you can tell whether it's a man or a woman by looking at the word "the" - el or la.

                Example:   el estudiante male student       la estudiante female student

2. Nouns that end in -ist in English only have one form and can be either gender. (Ex: artist, dentist)
    Those words end in -ista in Spanish. If it's a person, the word the will indicate gender: el or la.

                Examplesel artista is a male artist         la artista is a female artist.
                                 el dentista is a male dentist    la dentista is a female dentist.

3. Nouns that end in -tud in Spanish are always feminine.
                Examples: gratitud, multitud

5. Words that end in -tad or -dad in Spanish are always feminine.
                Examples: universidad, dificultad 
6. Words that end in -sión or -ción in Spanish are always feminine.
                Examples: televisión, educación

7. Some words came into Spanish from the ancient Greek (instead of Latin, where most words in Spanish came from).
Many of these words end in -ma but are masculine.
                Examples: el planeta         the planet
                                    el sistema        the system
                                    el programa    the program
                                    el problema     the problem
                                    el clima             the climate
                                    el día                 the day
                                    el poema          the poem
                                    el idioma          the language
                                    el drama           the drama
                                    el tema              the theme
8. There are a only few words that end in -o but are feminine. 
The only ones I can remember are la mano (the hand) and la radio (the radio).

9. Some feminine words that start with the letter "a" use the masculine the - el - so the sounds don't run together.
        el agua fría = cold water
        el águila calva = bald eagle