My GM instinct is to give bonus fortune dice on a check when PCs do something that would give them an advantage (e.g. getting the high ground in a swordfight, playing upon the vanity of the duchess, improvising a pulley system to help them open the door to the ruin).
But I've realized that WFRP provides a better solution. Instead of giving PCs a fortune die to the check, give the party a fortune point. That way, the player can spend a point of his fortune if his PC needs the bonus, conserve it if he doesn't, or even pass it on to someone else. Fortune is a party resource, so players encourage each other to think creatively and act in ways that generate fortune, and the table has more energy.
I used this method at a one-shot game recently, and it worked great--players roleplayed their characters really well, took some risks they might have otherwise not*, and spend fortune much faster that they otherwise would have.
*but still wisely ran away from the deadly horde of beastmen at the end of the session. This is Warhammer FRP, not Dungeons and Dragons.