Here’s a thumbnail I made for one of my YouTube videos, everything including the grass is made by me (I followed a tutorial to make the grass anyways). Any feedback is appreciated!
Speaking of the white flowers, they really stand out from the grass; the stem color is a bit darker. Maybe make the stem color match up with the grass.
The thumbnail looks great. One thing I would suggest is that for the “SUBSCRIBERS” text, maybe you should add an outline on the text and/or add a drop shadow for that text. Also, for the text “1,500” and “SUBSCRIBERS” have more spacing between the two text labels than needed maybe put the “SUBSCRIBERS” text a bit more up. Overall, looks like a great thumbnail.