It can be very difficult to properly fret your guitar strings if they are raised too high off the fretboard. Luckily, the height of the strings above the fretboard, called the action, can be adjusted on most guitars. Moving the strings closer to the fretboard is relatively simple on electric guitars. In general, it requires nothing more than turning a few screws. On acoustic guitars, however, this is a far more invasive task.
Examine the bridge on your electric guitar. If each of the strings have an individual saddle, like most Fender guitars, you will need a small allen wrench in order to lower the height of your strings. If your guitar has a stoptail bridge with an independent saddle piece, common on Gibson guitars, or a locking tremolo unit, you will need a screwdriver to adjust the height of your strings.
Lower the height of your guitar strings slightly. If you have a guitar with adjustable single-saddle pieces, turn both small screws on each individual saddle piece half a turn clockwise. On Gibson-style bridges, turn the two screws at the top right and left of the saddle clockwise for half a turn. Turn the two screws at the top right and left of the bridge piece half a turn clockwise in order to lower the strings on a locking tremolo bridge.
Play every fret on your guitar to see if the strings are close enough to the fretboard yet. If they are still too high, lower the action at the bridge a little more. If the strings begin to buzz, you have lowered the height too much.
Take the strings off of your acoustic guitar and rest it on a flat surface.
Grab the center of your guitar's saddle with a pair of pliers and pull straight up off of the guitar body. With a bit of force, the saddle should slip right out.
Measure 1/32 of an inch from the bottom of the saddle and draw a straight line across the saddle at this point. It is very important that this line is straight.
Sand the bottom of the saddle to the edge of the line you drew.
Force the saddle back into the slot on the guitar bridge with your hands. Don't worry about getting it extremely tight, the pressure of the strings will push it back into place.
Restring the guitar and play it for awhile. If the strings are still too high, repeat this process.
Take your guitar to a guitar shop and have a repair person adjust the truss rod if these techniques do not bring the strings closer to the guitar body.
If your acoustic guitar has screws in the bridge, turn these screws to adjust the height of your strings. These types of bridges are not common on acoustic guitars.
Only sand off a very small portion of an acoustic guitar saddle at a time. If you sand off too much, you will have to buy a new saddle.