Is there a general rule on what size trailer to use with what weight of jig?  I know the "bigger" heavier the jig the larger the trailer you could use but for example does a 3/8 oz jig generally use a 3 inch trailer?  

Rules! I don't follow now rules

3/8 oz jig: 6 Hawg Craw Cut 1 ½ off the tail leaves 4 ½ , 3 ½ Zoom Salty Pro Chunk, 3 Zoom Swimmin' Chunk, 3 ¼ Uncle Josh Phantom Craw, 3 Uncle Josh Crawfrog

It's all good

Rules! I don't follow now rules

I just look at the jig and say to my self "it still needs a bigger trailer". Then I fish it for all it's worth till I can find something bigger.

The west coast swimbait guys love them big old 6 oz swimmers, but I like a 1 oz Arkie jig with an extra skirt and a 9" Black widow eel for a trailer.

Ronnie

Nope, no rules.

I generally fish 1/2 oz jigs. Trailers run the gamut:

small: GYCB Fat Baby Craw,  GYCB double tail grub

medium: GYCB Kreature, Uncle Josh Pork

large: GYCB Flappin' Hog

x-large: Reaction Innovations Beaver Double Wide

8-)