OMG, that face lol, he's sooooo cute.
I wouldn't worry about a perfect haircut, from the photo it looks good to me. Have you shaved all the hair off the back of his ears. When they are young and ears are not erect, shaving off all the hair from the back of the ears can help keep the ears erect, hair is weight.
You'll get better at the hair cutting with time.
Thanks for sharing your photo, Flint is growing fast