/   Indicates a separation between two thoughts (usually sentences) 

< foo > Angle brackets are used for quote marks, and are representative of the mouth of the speaker producing the words which then enter the ears of the listener.

[ ] Square brackets surround a proper noun, like the cartouches in heiroglyphs.

~ foo ~  Surrounding tildes are roughly equivalent to our parentheses. They typically indicate an optional phrase. They are reminiscent of waves, bringing a thought in and back out. It wouldn't matter much if you missed one wave while watching the ocean. 

~ A single tilde outside of a word is used alone to indicate a pause that is typically indicative of a minor separation of thoughts, but not to the degree of a sentence separation. 

~ A single tilde within a word indicates a doubling of the vowell it follows.