Step #1: Solder up the 3904
Hold the 3904 in a helping hands and solder the base (middle) pin to one end of the 4.7k resistor. Then solder the collector (right, as you read the markings) to a 2 inch wire and to 1 of the 30k resistors. Lastly, solder the emitter (left) pin to the negative (black) wire from the battery holder and one wire from the speaker.
Step #2: Solder up the 3906
Solder the base (middle) pin of the 3906 to the 2 inch wire you soldered in the last step. Solder the emitter (left) pin to the positive (red) wire from the battery holder. Finally, solder the collector (right) pin to the other wire on the speaker and one lead of the 0.01uf capacitor.
Step #3: Solder up the last connections
Solder the other lead from the capacitor to the other lead on the 4.7k resistor, and then solder a 3-4 inch wire in-between the connection you just made. Remember the 30k resistor you soldered earlier? Solder another 30k resistor to that one (the first on you soldered). Repeat again with the last 30k resistor by soldering it to the other lead of the one you just soldered. Solder a 3-4 inch wire to the last 30k resistor. (Optional) Cover everything in heat shrink tubing or electrical tape.
Step #4: Mount the circuit to the pencil
Put the end of the zip tie through the locking part and use it to mount the circuit to the pencil. Use tape if the circuit keeps moving around. Strip one of the wires and wrap it around the pin's metal part. Push the pin into the pencil until your're sure that the metal part of the pin touches the inner graphite. Then tape down a layer of foil on the part of the pencil that is below the circuit. Sandwich the other wire in-between the bottom layer of foil with another layer of foil. Make sure you don't cover most of the foil! (Unless it is conductive.) Your're done!
You can put it in a jacket, or a paintbrush, or a tree, or even the kitchen sink... The ideas go on and on.