Models are an important part in the screenshot itself. It makes the screenshot have character and individuality and can make the screenshot very enjoyable.

It's SUGGESTED that you use High-Definition and Highly Detailed Models with very manipulative bones to create the perfect screenshot. The most manipulative models can do more poses, more things than the average default models. Default models may look like they can do a lot, but it's really animation scripts stretching the bones, etc. to make it look that particular way.

So, go from this.



To this.

Post-Processing are necessary towards the screenshot, unless you want it to look very UN-PROFESSIONAL

To make something look like this...



Rather than, this...



I suggest, using post-processing.
Although tweaking and messing around with post-processing can be a painus in the anus, it'd be best to do it to make the screenshot, worth it.

BUT

Some screenshots do not simply need post-processing. Such like this.



This screenshot is perfectly fine without post-processing.. So, proceed to what would look best in your opinion.

Camera angles are VITAL to certain screenshots.

For example in these...





A standard angle couldn't really be made, so, compromise. Try taking all the photos in angles and compromise on what looks BEST.

(FYI: To adjust camera angles, try placing a few at a time..Also, you can tilt the camera and move it forward or backwards. Hold right click and move the mouse at will!)

The certain poses in some screenshots can vary.
If you're making a realistic screenshot, try to take one without an arm glitching through someone's face or torso.. Because, in real life or real life logic, that really wouldn't happen.

Something realistic can be like this



It really varies on what you're trying to do, if it's with zombies, do something that would involve someone killing or going against the Infected.



Like this for example. I got out of my chair and wondered what it would look like to be cornered along the ground against a wall holding a weapon and aiming it at a zombie. I did just that and boom, made that. It's simple if you could analyze the simple movements, simple angles and poses a real life person could do.

Addons could vary, between simple things, but have your free will towards certain addons to make screenshots. Try going for Face HMV which will prevent your TF2 Face or HL2 Face to glitch out and look like a demon-spawn from Hell.

Ex.



Please don't make it look like that...
XD

Then there are Effects, like explosions in a scene or..Gun shots, tracers, fighting, etc.
Which, in-fact, I recently did a screenshot regarding a firefight between Combine Forces and Rebel Forces taking place in Episode Two.



The Addons I use in some screenshots would be these! I take no credit, all credit to producers of the addons.
1- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=104634865

This allows you to no-collide things with the world, preventing some hinderance in your screenshot production!

2- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=329174479

The extended emitter lets you do many things, make tracers occur, and more gun fire flashes. It's pretty cool and it helps with shooting scenes! I suggest it heavily.

3- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=576040807

The invisible material shall help with hiding things unwanted in the screenshot, for example an emitter for effects.

4- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=242776816

This would most likely help with campfire scenes, or something else in TF2 or in a ruined area scaped place. I suggest it heavily.

5- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=833180551

This addon can help dense up the screenshot well, with some effect!

6- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=225481532

This is almost close as addon number 4, but can be helpful to add some cool effects.

7- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=833625997

This would assist with face posing, I recommend it if anyone wishes to do some mug shots/etc.

8- https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=104604709

This is a good way to get started with screenshots, use already inputted animations and freeze it at the right time to pose it right! I suggest it for simple and fast screenshots, not hardworking and very detailed ones!

If I missed anything, please comment what I missed.
I'm happy to add anything else, and it'd be good to have some constructed criticism towards this guide.

I hope this guide was helpful in its properties.

Thanks for reading.
Good luck with your screenshots.