I have a keyring with several cards like that on it, which I keep with me for reference when needed. I have one with several bullet points covering things I can do when I'm overwhelmed (deep breathing, listening to music, asking for a break, etc.), one with ways to deal with anger (mostly energy-diffusing techniques like running or bouncing on my trampoline, things that will physically divert a meltdown), one with a list of ways to say "no" to people (something I have trouble with; the card is also a good reminder that saying no is okay), one with a handful of basic small-talk conversation starters, and one that's just a warning/alert card for others, with a large stop sign on it, along with the phrase "Shutdown in progress, do not disturb" for times when I've shut down and can't deal with being disturbed.
One recommendation I would make is be as specific as possible. What does "conversing properly" look like? Perhaps, "say hello", "smile", "shake hands", "ask, 'how are you?'" etc. I find that having all the steps written down is very comforting, because even if I have them all memorised now, they may fly out of my brain when I'm under stress and actually need them. Just something to consider.
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"Survival is insufficient" - Seven of Nine
Diagnosed with ASD level 1 on the 10th of April, 2014
Rediagnosed with ASD level 2 on the 4th of May, 2019
Thanks to Olympiadis for my fantastic avatar!