Whilst looking up images of existing types of punctuations, I ended up discovering that many people had created their own punctuation marks within the past of which not many people today know about or use. The page that I found them on included the following:
I am somewhat surprised to find out that there is currently forms of punctuation that I never even seen or heard of before. The fact that there are exciting forms of these punctuation may mean that the time I expected to come up with a feasible design may not be as long as I first imagined, as there is now so much inspiration in front of me to push me onward.
Looking at the more notable/interesting punctuations (e.g. sarcmark, doubt point, interrobang) has given me a few possible ideas at this time, which I will go further into within my sketchbook.
Source and Credit: