Acoustic/electric guitars give you the best of both worlds, but can be problematic to set up. If you know the right procedures, you will be able to make a few changes that will get you the most out of your guitar.
Replace your strings with thinner gauge strings. Light and extra light strings will make the sound of your guitar brighter and crisper. Thicker strings last longer but have less brightness. This is a matter of preference when it comes to sound, so experiment to find what seems right to you. Remember, thicker strings are harder to play.
Choose a high-quality brand of strings. Regardless of their gauge, nothing can make up for the sound of low-quality strings. Many acoustic players choose Martin strings, as Martin acoustics are widely regarded as the top of the line. Other top choices include Dean Markley and DR. With strings, you get what you pay for.
If you regularly use a pick, try different thicknesses and different materials until you find the sound that is right for you. Many beginning players overlook the importance of the right pick. Common plastics in use today are tortex and nylon, but other options include metal, felt and a host of other materials. Buy one of each until you get that perfect sound.
Purchase an amplifier that is designed to be used with acoustic/electric guitars. While a normal electric guitar amp will work, it will not draw the best sound from an acoustic guitar.
Use an instrument cable made with high-quality metals, such as gold and platinum. While they are more expensive, they will last a long time if you take care of them, and they will transmit the sound more accurately to your amplifier.
If your guitar was on the cheap end, consider changing the pickup. Some pickups on cheaper acoustic/electric guitars have the quality of a computer microphone. If the pickup is not reproducing the sound properly, no amount of cables or amplifiers can fix this. Consider EMG's ACS system, which is low-cost and fits into the sound hole of nearly any acoustic, limiting the amount of installation work you need to do.
Strings can get expensive. Buy in bulk online, and you can pay the same price as you would in a store, but get three to four extra packs of strings.
Tortoiseshell picks are a great find at flea markets and garage sales, but are hard to come by. They were banned decades ago to protect declining tortoise populations, but they have a unique sound and last practically forever. Pick these up if you see them.
Don't neglect the tone settings on your amplifier. Adjust the high, mid and low until your tone sounds balanced to you.