I would like to go out on a limb and say that I dont think its so hard to aquire a feel for the Federer forhand grip.
I think one thing we all admire about Federer is his natural, slingshot, through the ball forehand.
If you dont use a pistol grip, start by moving your knuckles upward and palm heel downward as much as your hand- and gripsize allow for a natural pistol grip (spread your fingers comfortably).
Grip the racket at the end of the grip so that the 3. and 4. fingers are (partly) on the butt. The tip of the fingers point more backwards in the pistol grip, so you might not have to move the hand back much longitudinally.
Now find the position af the racket that allows you to hit the ball well or purposefully with a natural slingshot. I think this can be done intuitively. If you go to much towards Eastern, you will be spraying balls all over the place (this is why I dont think its so productive to say "F. plays eastern..." or "F. plays continental...", "...but his uncanny abilities allow him to hit the ball in a way that is impossible for us other mortals to emulate...").
If you go to much towards western, you will struggle to get enough lift on the ball, and brush it more than hit through it.
Ofcourse there are other factors to get under your belt, such as hitting zone, body position, balance and timing. This is where the fun and frustration starts. I think the ideal hitting zone is in front of the body, at (or just after) the point where the natural slingshot movement starts to pronate (move over the ball). This point can be visualized in shadow hitting (without a ball). If the ball is not in this zone, you will have to adjust, maybe with the buggywhip shot (if you're late), or a more pronounced windshieldwiper shot (if the ball is to close to the body), both used by Federer amo.
The same steps can be used for the onehanded backhand, but its a bit more difficult to get the results here (due to natural physiological circumstances, imo). We can comfort ourselves with that it seems so for Federer also at times.