Step 1: Keep it casual
Avoid using all your flirting techniques in the beginning. You want to catch him when he least expects it. Unlike a dinner that will require the both of you to dress up and look somewhat formal, rather invite him for after-work drinks at a local bar. The vibe and scene there should be relaxed so conversation can flow easily with no pressure.
Step 2: make it about you
Remember the trick is not to come across too strong and risk scaring him off. If he’s someone you talk to every day, you could casually mention that it’s been a while since you’ve been to the cinema. Like the lady you are, you’re going to ask him to tag along if he wants. This way you end up being on an unofficial date without even realising it.
Step 3: Involve your friends
If you’ve tried doing it solo and didn’t work out then involve your friends. It’s always easier showing a guy some attention if you’re in a group because you don’t have be with them all the time. Once you’ve established where his mindset is suggest that the next time you go out let it just be the two of you, then give him time to think about it. Seeing you having fun with others will sure make him curious as to how it would be like if it were just the two of you.
Step 4: flirt your way up
By now you should be knowing what he likes and doesn’t so use it your advantage. If he doesn’t have a shy personality try looking into his eyes and see if he’ll do the same. Or if he’s the expressive type play with you hair or subtly touch his shoulder when laughing. That should definitely strike up a spark.
Step 5: Ask him
You could succeed with only just giving hints but the best way to do this is to tell him how you feel. Your gut will never lie to you so listen to it if it tells you that the guy feels the same about you.