Getting back to basics, you'll probably remember some of the rough-and-ready rules that you learnt, to remind you how to use the correct gender for certain nouns.
Let's do a quick recap:
If it ends in 'o', it's masculine
If it ends in 'a', it's feminine
If it ends in 'ción' it's feminine
If it ends in 'umbre', it's feminine
If it ends in 'ama' it's masculine
You probably know a few more, but you will certainly have found that, while they're useful guidelines, they're not always right.
How about 'la mano'?
and 'Mama' ends in 'ama' but she's not (usually) masculine.
There are other groups of words, too, which share an ending, but seem to have no reason or rhyme to their gender
So how do you remember the gender?
Thankfully, there's a trick you can use, which works quite well in Spanish, simply because most adjectives must 'agree' with the gender of the noun they describe.
So, if you can remember a combination of a noun and an adjective, it makes it a lot easier to remember the gender of the noun.
Let's take an example.
How about 'nube'? (cloud)
There's no handy rule you can apply to remind you of the gender but I always remember it with the phrase 'las nubes negras'
This just happens to be a phrase from a Gloria Estefan song 'Te tengo a ti' (aren't I always saying music is a great learning tool?) but I won't ever forget that 'nube' is a feminine noun
Another example 'torre'.
My key phrase here is 'las torres gemelas' (the twin towers)
Now, whether that reminds you of the World Trade Center, or the second book of 'Lord of the Rings' is immaterial, but it reminds me that 'torre' is another feminine noun.
So, looking back at the words I mentioned earlier, how about
'manos limpias' (clean hands)
'un coche rojo' ( a red car)
'leche fría' (cold milk)
'una mente aguda' ( a sharp mind)
'una fuente escondida' ( a hidden source)
'un puente largo' ( a long bridge)
'dientes blancos' (white teeth)
So, over to you.
Make a short list of problem nouns and have a go at creating some brief descriptive phrases to remind you of their gender.
I hope you find it useful.
¡Hasta la próxima!