Be in the right place, in the right time. I caught a guy blushing when he pulled an accidentally dumb move around me ;) It was so cute.
I know this may sound inappropriate to why you want him to blush, but one good way is to say, when with his friends, "when am I going to see that thing you keep waving in your pants at me with. Its always a focal point when I look, so just wondered if I was ever going to see it." This is in a way a compliment and won't have him taking it the wrong way where he gets upset with you, but it will make him blush, because having a girl say something like that out of the blue when your unprepared for it really will have him smiling and laughing but red as a beetroot, good luck,x
Grab his penis
If you give him a sincere compliment, he might.
Be nice and compliment him but be sincere about it :)
Please don't do that but just compliment him if you really want to
Just flirt with him and compliment him. If he likes you and is shy he'll most likely instantly blush
Depends on his personality. If he's shy, just about any affirmation or flirtation should do the trick.
flirting is the best way and it's a plus if he likes you
You have to be someone that he likes... If you aren't a girl that he likes, then chances are he's not going to blush when you're around.
If he likes you smile and make eye contact and he might look away and blush but only if he's shy ...
Being flirtly & flattering works.
stare him right in the eye and tell tell him how amazing he is