Locating an electrical short.
 

(Note this does not work in all situations, it's entirely dependent on the amperage draw of the particular circuit.)

You'll have to track down the shorted wiring and stop wasting fuses.

So heres a tip,
1. Buy a generic 2 prong turn signal flasher.
2. Solder up two wires with spade terminals on one end and solder to the prongs of the flasher the other.
3. Yank the blown fuse and insert your wires from the flasher.
4. Yes the flasher will start clicking (it's a self-resetting circuit breaker).
5. Start either under the hood or under the dash your choice, and start shaking wire harnesses.
6. When the flasher stops clicking there is your short.
7. Repair the wiring, yank the flasher, and replace with fuse.

Nice trouble shooting tip.
Here I added a couple pics.
For those with bad ears you can also use a extra loud flasher.