Can you post some of them here on this thread... someone may be able to give you feedback.

do you know how

You need to upload them to a service like Flickr or imgur, and then use their BBCode shortcut to set up a link here. There are a lot of image hosting services out there, so choose one that works for you.

This is an excerpt from the Rendering Section Rules thread (link here):

External services
To showcase images not following the Mecabricks rules for the render section, you have the possibility of using external hosting services like imgur.com which doesn't require any account. Upload your image and copy and paste the BBCode provided in a Mecabricks comment. It shall look like the following:
![https://i.imgur.com/ReSJdzH.jpg](https://i.imgur.com/ReSJdzH.jpg)
The tricky part is your link needs to be to the actual image. In other words, it needs to have a .jpg or a .png extension on it. You can't just copy the URL from the browser, nor can you copy the URL and add a .jpg or .png extension to it. Each service has a way to share images... look for the one that works with BBCode and use that sharable link.

Once you figure out how to embed images, the same code can be used for forum posts, model descriptions, model comments and private messages. They all use the same base system.