I remember learning por vs. para, and there are the two main ways English-speaking students are taught the differences between the two. The two ways are also what I HATED about learning por vs. para:
1) focusing too much on the "equivalent" translations into English
para is 'for', 'in order to,' 'by (due date).' Por is 'by means of,' 'because of,' 'for each,' 'for (substitution),' etc, etc, etc. IT IS EXHAUSTING to understand, and because por/para have DIVERSE contextual meanings, you would have to come up with many more English translations— and there is more! It's just too much mental work.
2) memorizing por vs. para as both meaning 'for'
Okay, if you read bullet point 1), you would see why this would cause SO many problems for English speakers. If this is how you currently know por vs. para — STOP. It's time to reset that brain.
Because por/para are two of the most diverse and meaning-changing prepositions in Spanish, the truth is that you'll learn most of their contextual uses through exposure and practice.
That being said, there IS a way to practice "training" your brain (ON YOUR OWN( to understand the context for when to use por vs. para by recognizing its potential use in your everyday English language. Because you are most likely not surrounded by a Spanish-speaking community, sometimes you have to get creative and use your native language to your strength in fixing this stump.
Read the following paragraph I made up (underlined phrases are expressions where each word needs to be said in that order):
Por the mornings I eat breakfast, and por the evenings I buy takeout. Por the Saturdays I have dance class, but por the weekdays I have school. I go to class por car, but some students get to class a pie ('by foot'). But para this day today (aka not part of my usual routine,) I walk por the streets and por the alleyways para get some exercise.
Anyways, my friend always arrives earlier than me para have time to talk with her friends and to quickly finish up her homework. She texts me por iMessage, and I always reply, Estoy por salir 'I am about to leave'. She freaks out, because the homework is due por 10am.
Para you, the difference between por vs. para seems confusing, but para me, it just took time to understand the contextual uses as well as the expressions that use the prepositions. Though I could be explaining this to you por video chat or on the phone, I am typing this message por laziness. Besides, I might talk por an hour!
I am answering this question PARA you, and POR your question. Por your question, I am writing this para you all. Por every question you have para me, there is an answer.
Study the paragraphs and go sentence by sentence and try to come up with a general pattern/context for when I used por vs. para.
For example, por is used in answering the following question about a routine of yours— when? The mornings? Saturdays? Weekdays? However, when it is out of your normal routine, then use para.