Overview
In this guide, I will tell you how to do a nice thumbnail for your creation. Remember to read the guides of how to add a custom thumbnail first to learn the basics. Let’s start!
Step 1: Taking shots
If you want a good thumbnail, remember to take shots properly. Take several shots from the creation (I prefer using FOV of 60) and decide which shot you are going to use for the thumbnail. For example:
As you can see, I took the shot from a not-quite-long distance. This shot works perfectly for the creation’s thumbnail when cut. For aircraft, I prefer taking shots while flying but, if it’s too difficult for you, then take shots on the ground like this:
Step 2: Cut the picture
Now, it’s time to cut the pic. I use Windows 10’s photos thing for this. To add more epicness, angle the pic and center the vehicle. To center the vehicle, use the squares shown while cuting/angling it. Don’t cut ANY part of the vehicle, though. You can see those squares here:
It looks nice, right? Angling pics make thumbnails look more cinematic and attractive, so I recommend you to do that on your custom thumbnails.
Step 3: Edit the thumbnail
It’s time to edit the thumbnail. For this, I still use the same app. If you want a clear pic of your vehicle, give it more brightness and clarity. You can saturate it if you want, but remember to not oversaturate it. 
(Optional) Step 4: Text
If you want to give some info of your creation, add some text on the thumbnail with its name, the amount of bricks or any stuff you think it’s important for people to know. I use Paint 3D for this. 
Here you can see how I centered the text and made it clear for people. Don’t type “— Bricks” though, I’m just giving an example lol.
Step 5: Insert your custom thumbnail
This is the final step. You can find several guides of how to add custom thumbnails. Remember the max amount of resolution is 512×512. Enjoy your epic custom thumbnail!