There is an article in the April 2023 issue of Toastmaster magazine titled Back to the BASICS that has a section on pages 16 and 17 titled 10 Strategies to Boost Your Gestures and Body Language. Under gestures it says five things:
1] Train yourself to gesture more.
2] Learn from the pros.
3] Create a gesture for each main point.
4] Observe yourself in action.
5] Have a dress rehearsal.
But it doesn’t say where to get those gestures. One good source is American Sign Language (ASL). The alphabet is shown above, and in a video. There is a comprehensive 600-page book from August 2021 (editor in chief Clayton Valli) titled The Gallaudet Dictionary of American Sign Language with 3000 entries. And there is a third edition of another shorter book from 2014 by Lottie L. Riekehof titled The Joy of Signing: A dictionary of American signs.
Where can you find a more compact set of ASL gestures to learn? At Open Lines on November 14, 2022 there is a blog post titled Sign Language: How to Teach Your Baby to Communicate describing eleven signs.
And there are books about teaching sign language to babies. My local Lake Hazel branch of the Ada Community Library has a 2018 book by Lane Rebelo titled Baby Sign Language Made Easy and subtitled 101 Signs to start communicating with your child now. Another 2021 book by Diane Ryan is titled Baby Sign Language: More than 150 signs baby can use and understand (easy peasy). There is a preview at Google Books that on page 67 discusses signs for eat and drink:
“EAT: Your hand moves back and forth – toward and away – from your mouth as if eating.
DRINK: Pretend you’re holding a glass and taking a sip.”
There is a Signing Time Dictionary web site with 400 entries (including brief videos) for both eat and drink.
Images for the first and final gesture for drink, and the ASL alphabet are from Wikimedia Commons.