Couple questions?  When do you want to use a football head jig?  When do you want to use a swim jig?  When do you want to use a finnesse jig? When do you want to use a flipping jig?  

football - rocks (shape of head wont get hung up as much)

swim jigs - anywhere (i fish them over grass usually with a baitfish colored grub, smoke, white etc.)

finesse - when bite is slow, clear water or to get more numbers (a round head is a decent "all around" jighead. less skirt shows off more of the trailer)

flipping - heavy cover (heavier hook)

the finesse jig is the best confidence builder if youre new to jigs IMO

Ok, heres how it goes for me.

Football Jigs: Rocky bottoms, as mentioned above.

Swim Jigs: I really don't have a specific time or know any clues to lead me to throwing a swim jig other then when the fish start hitting my swimming jig. Let me explain. I will throw a typical jig around, and if its rigged with a trailer that swims nicely, such as a ragetail chunk, doubletail grub, or paca chunk then I will cast it to the peice of cover I plan to target, slowly hop/crawl it along, and when the time comes to bring the lure in, I'll swim it back in. If the I start getting fish like this, I'll usually start throwing the jig all around swimming it. This is the only indication I follow for swimming jigs. I have found times where they wouldn't touch it while it was crawling/hopping but once I swam it, I'd start to catch. But as of yet I don't have a known indication of when a swim jig is the best bet to try.

Finesse jig: I use finesse jigs under a few conditions. 1. When im fishing in a area that has alot of small bass, and very few quality fish. 2. When the water gets cold, and the fish's metabolism slows down. 3. Match the hatch theory, if the bait is small, I want to be using a small bait myself , and 4. if the fish aren't taking the typical size jigs.

Flipping Jigs: If I'm dealing with alot of cover I'm going to throw a flipping jig, mainly because its made to be fished in the thickest of cover, and as Bigfruits stated the hooks are heavier. Good luck.

What they said

Good advice above..........

I would just add throw the football heads in deep water also.  15 ft + and fish it slow

I agree with everything above and deffinately football head for deep water

I agree with most everything that has been said and I will add a few ideas for the swimming jig.  I typically have found that fall is the best time for swimming jigs ( In my area of the country atleast) or also when you see brim sunning around the floating docks in the early springtime.  The jig can be a little more subtle than a spinnerbait in that situation.  

I fish football jigs when I am throwing at any hard cover I can not see (other than brush piles) and anytime I am covering water and want a different profile than a carolina righ.

I fish football jigs when I am throwing at any hard cover I can not see (other than brush piles) and anytime I am covering water and want a different profile than a carolina righ.

I agree with this.  I will throw a football head jig (1/2 - 3/4 oz) when I want to cover longer distances and drag the jig across the bottom, and I use it instead of a carolina rig when the fish are holding tighter to cover, or aren't quite as aggressive.