I don't know if you know, but I'm also in grad school, and I'm a distance education student. This means that I've been worrying about how to look decent on a web cam long before the Coronavirus hit! I have to do a lot of professional presentations for my degree, so I can't just look like someone who lives in sweatpants (even though sometimes it's true...lol). Here are my top tips:
* Makeup: you want to look polished, but not overdone. I'd focus on a tinted moisturizer, filled in eyebrows and lipstick/ gloss. Remember that your makeup always looks lighter on camera, so you can go a little heavier than usual. I'd also go for actual colors, versus a nude lipstick. Cameras will not pick up on subtle looks!
* Jewelry: aahh...you knew I'd get there eventually. Take a look at any female newscaster and you'll see that they always wear at least a pair of earrings on air. (Except Rachel Maddow, who rocks those awesome, bold glasses and needs no other accessories!). It's because earrings draw attention to your face, and if you get ones that are small and non-distracting, you'll look un-intenionally polished and professional. Below are some of my favorites from my new line.
* Clothing: pick a blouse in a flattering color. I would stay away from white or black because they can cause the camera to wash out or throw shadows on your face.
* More: don't worry about finding a blank wall in your house to sit in front of. Instead, change your virtual background. This allows you to upload a picture that your meeting software will use to replace your background. It's easy to do. On Zoom, follow these instructions. If you use another web conference provider, just google "how to change virtual background with xxx".
Also try to center your webcam at your eye level, instead of above or below your head. The former can make it look like you have a shiny patch on your forehead (from the ceiling light), and the later will make it look like you are a giant.