MMWT #3 don’t only make your characters blush and/or stutter to convey embarrassment. If you’re working with a big cast it may be easier to focus on using these two in order to save the time of showing EVERYONE’S different reactions but I still think spicing it up is important. Also with dark skinned characters it can be difficult to tell when they’re blushing on first glance because their skin isn’t paper colored so some red in their cheeks won’t show up like blood upon the snow (epic vocals)
Here’s some other stuff people do when they’re embarrassed. Usually it’s a combo of a few, but you can always write in your characters notes one of these that’s most prominent
Looking away/avoiding eye contact
Going quiet for a moment before taking a deep breath or swallowing and speaking (nervously)
Scratching the back of their neck
Finding some excuse to look away or doing something to avoid acknowledging (shuffling their papers, checking their phone, tying their shoe, etc)
Changing the subject (subtly or obviously)
Glaring at the person who embarrassed them
There’s probably more but I can’t think of anymore so that’s all I’ll list for now :)