Using a short remark from @NP5, I do a side tour.
WAR on COVID19.
I creates a syringe, wanted to make it glass/plastic. But that not cartoon like, so I abandon that idea.
Still “How to imply transparency as a cartoon shader?”
Images in Eevee.
Glass, transparency
More cartoon (expressive) like.
Awesome… 
Using an ICO-Sphere and a particle system, generating T-objects on vertices.
(I forgot how to fix one instance per vertice. So I generated a lot, then joined and merge by distance to remove duplicates)
The metal syringe is a more old style to go with the gas mask, helmet etc. But Perhaps too old?
How about having your glass syringe with a positively coloured ‘vaccine’ liquid. Then even without transparency in a cartoon style, you could have it being used, plunger going down turning the syringe from full green to empty white? A feature the metal one denies you. It is going to be small unless you do a close up.
Quick composition. Always difficult.
Not sure, which way I’m going.
One lamp (current a sun) or more. I like a flashlight. Dark vs light. Background … ? bottom floor … grass dirt? Color schema, field depth, vertices count … Eevee. Grrrr,
Update on syringe. Put some extra effort on the syringe glass/plastic tube.
Not glass used but old fashioned glossy and transparency.
Added (green) fluid plus air bubble. Which is too much I think.
I had a lot of troubles of rigging, in a simple way, this model.
I did some test poses and now I see the jacket is going wrong.
Not sure why. I think in the way the automatic weight is calculated and the shape.
I will use shape keys to correct this.
Have fun. And try out new things.
Can not get a good composition, lighting and color schema. It’s hard.
I love and hate Eevee. But working in Cycles is soo slow and and crashed when I want to render a box in the scene.
Cycles, nice transparent viruses and out-of-focus.
An eevee version.
I’m going to change the composition completely.
I am fan of your works… 
Certainly good ideas. Cycles every time.
Not sure you need to do the virus ‘T’ bits transparent?
Of course, the new scene requires other characters in trenches, well isolated in foxholes, wearing masks. That your ‘hero’ is coming to give vaccine to.
Today I had a deviation tour. Re-using another project parts for an idea I had on the
I did my best to make the puppet flexible in usage. But now in a different project. I encountered other problems. It’s a hard and tedious process. Also, a fight on when to apply modifiers like “mirror”, “solidify”, etc. Or when to combine meshes …
I have the feeling, Blender is never gonna be easy on every level.
But I had fun!
Great reuse of assets as a starting point. It is so helpful to get such things together.
Of course this scene is not child friendly, tin lids are sharp and dangerous for children to be playing with!
I had the idea to add smoke, but that is a cumbersome task for my machine. So I left this idea as an idea …
Personally I have mixed feelings about this project. Modelling is not a problem anymore. But the process afterwards, composition, lighting, materials, etc.
You need to see what the changes are and when your machine becomes slow, it starts to become an annoyance. But here we are! Learned a lot, especially “Preparation is the key”.
Have fun, stay healthy.
Smoke can be done by using a plane with a grey scale image or built in nodes and using the alpha to designate where it shows and doesn’t. This is much lighter on a system than volumetric fog/smoke. 
Yes, I know. I considered it.
It works, but I need volume following parts of the scene.
Like cold coming from an ice cube.
Not smoke ascending but the other way around.
I love this topic! I might have used most of my likes today in this topic (wasn’t aware that that was a thing) 
I had that problem many times … 
But, I think you get an award for this event.
My plan was to use this as a game asset. Working with game tiles using a 2D game engine in JavaScript (Phaser 3). But I have too many projects, few of them passes the finish line.
I know your pain. I have the same thing and have to remind myself to focus. I even made a jira board for a ‘project & learning roadmap’ to keep myself in check as I’m aware of my limitation and constant jumping between things. It helps a bit, but doesn’t solve the problem for me 
. Soo many things are worth doing and learning but the day have just so little hours . I’m starting to accept that is just my thing and I will have to struggle to keep on track to achieve my bigger goals.
Btw. I really like the way you documented all the steps of the process with wireframe and your thoughts. I bookmarked this thread so I can refer back to it. Especially I feel that the ‘making eyes with eevee’ video you linked will be super useful.
