Fisk Investment Seminar plays into the best trait of criminals - creating and exploiting weakness.
The flow of cards for the corp will always be: R&D >> HQ >> Remotes (or Archives). Think of F.I.S as pulling agendas from R&D into play before the corp can safely score them. With Leela Patel: Trained Pragmatist as a speed bump and constant Remote pressure, suddenly the corp starts filtering agendas for you in HQ.
Criminals running F.I.S aim to be faster than the corp. Needless to say, the draw efficiency is used to build up your economy, breaker suite, and ultimately threat. Slow down the corp and speed up your game with the typical criminal bag of tricks - Account Siphon, Emergency Shutdown, and even Bank Job.
F.I.S's true synergy lies with HQ Interface and Sneakdoor Beta - HQ Lock, the less popular cousin of R&D Lock. For the corp, being HQ locked means that any drawn agenda must be installed or trashed immediately due to the risk of them being stolen. What happens when they are unable to install or trash them safely? It gets stolen. F.I.S speeds up this process, denying the corp time to build up credits. Running on the turn F.I.S is played also gives a chance to access freshly drawn agendas before the corp can even touch them.
Here's a mid game example:
After playing F.I.S and installing your first HQ Interface, the corp would play their excessively drawn cards too. Typical glacial corps will spend their turns playing economy and layering up ICE on HQ, R&D and their scoring server. This leaves little to no ICE on Archives and very often at least one agenda in HQ - perfect for Sneakdoor Beta. You can be even more sure of this when you haven't seen a single agenda, yet an asset like Adonis Campaign is in the well defended scoring server. With your HQ Interface installed from the previous turn, it's time to work the back door.
Other utility cards include Inside Job to threaten big scoring attempts. Hades Shard to swipe agendas in Archives hiding behind Jackson Howard.
So, when to play this card?
Personally, I just play it when I need to draw cards on my turn. That's it. No fancy "timing is everything". The notable exception being hand-less corps. Let them waste a turn or two to draw up before playing F.I.S. Otherwise, a well balanced deck should be able to play F.I.S most of the time. There is no need to save it.