Yep, I agree with BA and Ceit -- I just tuck the very frontmost part of the top and let the rest drape down, creating almost a high-low hem effect across my body.
And you're right, not all tops do this well. I suspect your top here might be a tad short for the semi tuck. I like the effect very much on you, though. Keep trying! I think the semi tuck can be really helpful for giving some visual balance to a very short or long torso.
Fabrication and pattern can make a big difference in the faux tuck too. If the fabric is not drapey enough, it can sit funny and pouf out on the tummy. Not flattering. And I think it works best with a solid color top or one that has a uniform all-over pattern. Your top here looks like it may have a pattern difference at the hem, which may throw off the visual line of the faux tuck.
