Greetings friend @daltono, a pleasure to introduce myself, I was going through some publications when I saw yours, which caught my attention, I am a little new with this hive, but little by little I have been learning to improve my publications, (the truth I do not know if I'm doing well), at this time I could see some of your publications and I see that you have some beautiful thumbnails, I would like to make some like that.
I usually rely on publications about movies and drawing, in the movies I have seen that many place the cover of the same, but in the drawings I have noticed that only place the image of the final result of the drawings, I only follow the example of others, but for a professional like you, I would like to know if I'm doing it right, I would be very grateful with your comment, I also thank you for this type of publications, makes many newbies like me can learn more how to improve their publications.
I'm very glad you commented, because I have a lot of information for you that will help you do even better than you already are.
Firstly, I just took a look at your page. Your reviews look really good and I like your use of custom designs and you have good taste in movies. Using a high quality image of the movie poster is an excellent idea.
The way that I'd change your thumbnails to make them more personalized is by turning those vertical posters into landscape rectangular images. You can do that by adding a background, maybe other images, and text. I've linked some apps at the top of this post if you don't already have some.
I'll also send you many examples of how I used to do my movie review thumbnails. I've written many over on CineTV. I even have a collection with all of my movie posts in an easy to find place. Here is the link https://peakd.com/ccc/daltono/movies-and-tv-shows
Let me know if you have further questions. I think once you look at my movie thumbnails, it will give you a great idea where to go with your own.