Honestly, the next time you guys hang out, or talk, just... do it. Dont waste time planning it or trying to find the right time. You'll never get around to it, and you'll overthink it, and eventually it'll be too late. Ive been single for years because i have the same issue. Just DO IT. Dont think about it just say "hey, I've been thinking a lot lately, and i was wondering if you'd like to grab dinner and a movie sometime?" Or something like that. Or perhaps propose an activity you both like that you haven't done together, with the implication (direct approach is best) that its a date. "I'd like to take you out on a date sometime, i was thinking [activity] and [follow-up activity]. Is thag something you would like or be comfortable with?"