aaahhh IGF - love the stuff.. I have had some of the most intense pumps I have ever had when I have used IGF..
I have run it a few ways....
Pinned just pwo
Pinned through the day in each working muscle
Pin the same muscle eod/e3d for 4- 6 weeks
Pin the working muscle 3 hours before training
Pin the working muscle 1-2 hours before training
Rotated body parts - legs one day - chest another - biceps another etc etc
now as for localized growth I personally think it works and I have studies that show evidence of this also, I can dig them out for you if you like.
I pinned the Vastus Medialis (Tear drop) for 6 weeks e3d with 40mcgs and did this cycle twice there was a definite improvement in the size of the muscle.
My favorite way of running IGF is pinning the muscle pre work out - If I am training say chest and biceps I would would pin the chest 6 hours out from training and then pin the biceps 3 hours out from training - this way my strength increase was very noticeable and the pumps were incredible.
Now If I pinned a working muscle 1-2 hours before training I would not get the same effect as I would at the 3 hours mark. As IGF has a water based carrier I have no idea why this would be.
The most I have done is 3 body parts through the day - ie chest, biceps and triceps...
The other way I like running it is pinning a body part even if you are not training it. I would pin biceps for example even if I was not training that body part on that day and you would still get great pumps if you did squats

IGF is going to work no matter how you run it but I think its always nice to "feel" you are getting something from it. The only time I did not feel anything was pinning it PWO but this does not mean it was not working.
I dont go over 80mcgs in each shot (40mcgs in each muscle) and as IGF has a life span of 17 hours it really does not matter where you pin it it will get to the places in the body where it is needed