When I want to count seeds instead of just using a small measuring spoon, I use a small liquor glass around 3 inches tall. Near the top, it widens a little to a "belly", and then narrows again.
When I hold it nearly horizontal, the "belly" will hold seeds without dropping them, even if my hand shakes.
So I can put a tablespoonful of seeds into the liquor glass, hold it nearly horizontal, and shake or scoop around the right number of seeds into the "belly".
Then I use a small spoon or knife to spread the sees out and move them back or forward until I can count them as I drag them forward over the lip and drop them into tray or cup.
