American Sign Language: "c"
c:
Rookie mistake: Turning your hand sideways when spelling the letter "C."
There is no need to deliberately turn your C hand sideways when fingerspelling. Skilled ASL signers can read fingerspelling from nearly any angle -- and if we miss a particular letter we can usually still figure out the word from context.
Just hold your hand up in a naturally comfortable position and spell. Don't focus on "aiming" your hand in any particular direction. Those of us who fingerspell hundreds of thousands of words in our lifetimes are *not* going to hold our hand at an uncomfortable angle when chatting with our friends and close family members. If you see it done online it is because the person showing the spelling is overthinking it and putting in more effort than typically occurs in natural signing environments.
Hearing people distort their voices when talking to babies (often called "motherese"). It is cute when done to babies -- it is not cute and not at all necessary when conversing with skilled language users.
If you spell something in a natural way and your conversation partner doesn't get it the first or second time then, sure, go ahead and slow down and aim your hand a but more towards your signing partner. However such changes are the exception (in real life conversation) not the rule.